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· One min read
Erik Onarheim

Excalibur version 0.7.0 is now available! This is a very exciting milestone, as we have added a major feature!

New physics system

We’ve implemented a rigid-body physics system, complete with edges, circles, and convex polygon primitives. This enables you to build fully-featured physics games in Excalibur! Fear not, the old physics system is still around for you to use.

a demo of the new physics system, showing birds with a knight helmets being thrown into a tower of blocks to knock them over

Generic lerping and easing

Excalibur now has generic functions for lerping and easing!

the new Excalibur easing function autocompleting in a code editor

the results of the above code, causing a bird to move according to a cubic easing function

Code cleanup

We’ve removed a number of deprecated methods. Check the changelog for a complete list.

Contributing

We have improved our contributing document to make it easier to jump into Excalibur development. If you’re interested in helping out, read through our new Contributing documentation

Overall there were over 27 issues addressed in this release. Check out the full release notes for all of the details, including bug fixes and enhancements.

· 3 min read
Erik Onarheim
Jae Edeen
Kamran Ayub
Alan Grgic
Sean Igo
Ante Grgic

Hexshaper game screen: a witch flies a broom around a large room, dodging green projectiles and bats

Ludum Dare 35 is the fourth in the series for the Excalibur.js team. We piled five to seven people into one room for four days to make another game.

What went well

Workflow and toolset

We’ve continued to refine and improve the way we build games for jams. It’s important that everything “just works” as much as possible. We maintained the same continuous deployment process that we’ve used before to push to a live site, so it could be tested and played within a minute of being checked in. We also used a watch-and-compile task in Visual Studio Code to gain the same benefit while developing locally.

Art & sound

the witch, bat, heart, and torch art assets from the game

We had four people putting together art assets on and off throughout the weekend, and it turned out great. We used bfxr to create the sound effects, and a set of littleBits components to compose the background music. Once we had settled on the theming for the game, everything fell into place.

a set of littleBits electronic music components attached to a pair of headphones

Event scripting

We initially had a grand plan for introducing elements of Hexshaper, and as usual we had to set that aside and come up with a more practical solution that could be completed in the time remaining. We ended up pausing the game and moving the camera over to each portal as it opened and as the player successfully closed it, which ended up providing most of what we wanted.

Bugs

We only encountered a few bugs in Excalibur this time around, and they were all relatively straightforward to test and fix. It feels better to use the engine each time we do a game jam.

What didn’t go so well

Minimum viable game

the original prototype for Hexshaper, a spaceship surrounded by a green hitbox

We didn’t have a very clear vision of what we wanted the game to be this time around. Uncertainty translated into not really having a playable game until Monday. This delay was a stark departure from the last couple of games we’ve made, where we made a point to have something relatively complete by Saturday evening so we could iterate on it through the rest of the weekend.

Animations

There were a number of things that made interacting with the Excalibur animations API painful. Luckily, we didn’t lose too much time to them, and we now have an opportunity to improve that experience for future users.

Conclusions

  • Build a playable game as soon as possible
  • Look for alternative solutions that create most of what you want for much less work

Special thanks to all of the people who worked hard to make this game possible!

timelapse of a room full of people working on building Hexshaper

· 2 min read
Erik Onarheim

We’ve been steadily working on the newest release of ExcaliburJS, and it’s finally here! Version 0.5.0 brings with it many new features!

Controller support

controller support input detection

Excalibur now supports the HTML5 Gamepad API. Most modern controllers can be used as game input.

Z-indexing

demo of z-indexing, showing a robot moving in front of and behind a cactus

You can now specify layering for actors in your game. Higher index values draw on top of lower values.

Faster collision detection

Excalibur now uses an axis aligned bounding box tree for better performance during collision checks.

New documentation

demo of documentation search bar autocomplete

The Excalibur docs are now cleaner and easier to navigate. Use the search bar at the top to help you find what you’re looking for.

There are also a number of improvements and bug fixes to make Excalibur faster and easier to use. If you’re so inclined, check out the full release notes.

Releases are also available in Bower and NuGet; please reference the installation guide for more information. If you’re brand new, welcome! Check out the Getting Started guide to start working with Excalibur.

The main Excalibur branch is constantly being improved by the team. If you crave living on the edge, reference the edge documentation to keep up with what we’re working on. It is automatically updated with every commit.

If you’ve used Excalibur for a project, please send it our way so we can consider showcasing it on the website!

· 5 min read
Erik Onarheim
Jae Edeen
Kamran Ayub
Alan Grgic
Sean Igo

screenshot of a partially-played sweep stacks board, showing various colored swuared in stacked columns

Play the Ludum Dare version of Sweep Stacks

This game jam was the second Ludum Dare we've participated in. Our goal with Sweep Stacks was to build something fun and see how well we could work with a larger team (five people instead of the usual three).

What went well

Preparation

Given the problems we had last time with setup, we made sure that everyone prepared their development environments ahead of time, and brought over their computer equipment to set it up the day before. We also configured continuous deployment for our code using TravisCI and GitHub Pages. This ensured that every time we pushed a change to the game, it would update on the website and we could see that the game was working properly.

Brainstorming

We came up with a number of ideas for this jam, several of which everyone seemed to enjoy. Even after we had those concepts moderately well-formed, we kept trying to come up with more ideas. After we’d exhausted our collective creative capacities, we made sure everyone was on the same page and went forward with the idea we all liked the most. We used Trello for new ideas or issues that we encountered; it was incredibly helpful to organize everything, and we highly recommend it for game jams.

Scope

We made a concerted effort to keep the scope of this game small. The theme definitely helped with that as well. Once we had the initial mechanics drafted for matching and piece movement, we realized that we could actually do a physical prototype. We pulled out some poker chips and a checkers board, and played the game for a while. This was immensely helpful for quickly visualizing exactly how the game would work, and allowed us to check for potential problems without having to write any code. By keeping the scope small, the game was playable very early on in development, which allowed us a lot of time to tune the gameplay.

physical prototype of Sweep Stacks, using a checkerboard and various colors of poker chips

Testing

One of our team members, Sean, offered himself up to be our dedicated game tester for the weekend, and it was absolutely phenomenal how much it helped the development process. Coupling this with our continuous deployment meant that we encountered bugs or potential issues very quickly, and could either remedy or improve upon them easily. We also made a number of features easily configurable so we could test different board sizes, block distributions, and other changes.

Art & sound

Another team member, Alan, brought over his guitar, so we decided to try and use it for sound effects and music. After about an hour or so, we had the music and notes that you can hear in the game. They turned out great, and really added a lot to the atmosphere we were trying to create.

Earlier on during the weekend, we had tossed around the idea of a fantasy theme for the game. In the end, we decided on a simpler art style, which ended up looking really good, and helped us focus a bit more on the gameplay rather than on designing or incorporating more complicated assets.

Timelapse

We recorded timelapses on our computers while we worked, and also had a camera running on the room we were all working in. It was fun going back through the pictures and watching the game develop. We’re putting together a video or two of the process, but here’s a short teaser for now:

sample timelapse of us in the room we were all working from during the game jam

sample timelapse of various iterations of the game, showing graphics and layout improvements over time

What didn't go so well

Analytics

We used Google Analytics to keep track of scores and a few other stats. However, due to a limit on how many events you can send (one event per second after the first ten events), we can’t properly record all of the events if a user plays more than one game. Next time we’ll try a different analytics provider, or consider our own solution.

Hosting

Github Pages went down for some unplanned maintenance a few days after Ludum Dare was over. We didn’t have a fallback hosting solution set up, which meant that there was a fair amount of time where people simply couldn’t play the game. We now have an alert set up for our current hosting and a fallback site on Microsoft Azure ready to deploy if anything goes wrong.

Bugs

Excalibur was much more stable this time around, although we did encounter a few platform-specific issues for iOS and Windows Phone that we could have been aware of sooner if we’d playtested the game on those devices.

Color palette

Our final color palette ended up being very unfriendly towards color blind players. We’re currently working on different color selections for color blind modes, and we are definitely going to consider accessibility in our initial design decisions from now on.

Future plans

There has been a fair amount of interest in Sweep Stacks so far, and we've definitely had a lot of fun working on it, so we plan on continuing to develop and improve it further. You can play the most recent stable version of the game at playsweepstacks.com.

Conclusions

  • Create the smallest game you can make, then build on it from there
  • As soon as your game is playable, have someone play it
  • Have fun!

Ludum Dare 31 was an absolute delight, and we hope to be back again someday!

· 7 min read
Erik Onarheim
Jae Edeen
Kamran Ayub

It’s taken a while to get around to composing this from the notes we scribbled down after the jam, but here we go!

What went well

Teamwork

Overall, our team worked really well together, given that this was our first “high-stakes” deadlined project. Being able to work in the same physical space was a big part of our productivity over the weekend, and we were able to help each other with problems or changes quickly and effectively.

Planning

We felt it was important to spend an appropriate amount of time discussing ideas before we settled on making anything. This turned out to be several hours. We took a walk around the neighborhood and brainstormed ideas that would fit within the theme, eventually settling on a much more elaborate version of what would become our game.

Sleeping & eating

While Ludum Dare takes place within a limited time frame, we had no intention of staying awake for the entire duration. Overwork and sleep deprivation leads to inefficiency. We also made sure that we remembered to eat food at regular, human intervals. This helped maintain a positive mood and keep us from consuming each other and/or the neighbors.

Map editor

We decided to use Tiled to create our map. We spent a bit of time getting it to integrate with Excalibur, but being able to graphically edit everything in the level on the fly was definitely worth it.

Art & effects

animation of the kraken swimming across the screen on a blue background

Overall, our art process went better than expected. We leveraged an existing tileset for our geography and map background. We put together the ship and kraken sprites ourselves with Photoshop and Paint.net, and they turned out well with relatively few frames of animation. We used color blending to darken up the map, which really helped set the mood of the game. The ship spotlights were created using a radial gradient effect, which was pretty simple to do and looked great. Additionally, we added a little bit of camera shake into the game when the kraken attacks ships. This was easily the best payoff for the least amount of code.

Stats

The end-game score screen was a last-minute alternative to a boss fight that we cut from our scope. It ended up adding a good deal of replay value to the game, and encouraged players to come back and try to beat their previous score. We also hooked the game up to Google Analytics, which we think everyone should look into doing if they can. It helped give some insight into how people were playing the game, as well as give us an idea of how difficult the level was.

pie chart showing a 45.6% win rate for our players overall

table of win statistics: average damage taken: 61.53 (72 total events), average aggregate score: 39.42 (53 total events), average health gained: 32.92 (72 total events), average boats destroyed: 3.20 (74 total events)

table of defeat statistics: average damage taken: 120.38 (105 total events), average health gained: 20.38 (105 total events), average boats destroyed: 2.29 (105 total events)

TypeScript

If you’re developing a game using JavaScript, we recommend giving Typescript a try. Static typing really helped us during the rapid game-building process of Ludum Dare.

Testing Excalibur

One of the main goals we had in mind for this jam was to put our game engine through its paces. We were able to push the limits of Excalibur and find a number of opportunities for improvement. The more we do game jams like this, the more filled-out the engine should become.

What didn't go so well

Also testing Excalibur

On the same hand, we encountered several critical issues that halted game development for several hours each. Excalibur, still in early alpha, didn’t fully support a lot of the features we tried to use it for. While this was expected, we spent a lot of time fixing bugs and adding features to the engine instead of working on the game. Next time, we plan on prioritizing quick workarounds when we’re in a time crunch.

Deadlines

We often didn't stick to our self-imposed deadlines. For example, we had planned on halting development several hours before the submission time, but we ended up working until fifteen minutes prior to the end of the jam. In the future, we definitely need to timebox better and set more realistic goals around task completion.

Playtesting

As a result of ignoring all of our deadlines, we hardly did any playtesting of the full level. While this luckily wasn’t a huge issue in the end, it had the potential to be absolutely disastrous.

Game controls

The game ended up with slightly unintuitive player controls. The kraken followed the player’s mouse pointer, but we required you to press the spacebar to attack; we should have just used mouse clicks for attacking the ships. We also only played the attacking animation when the kraken was within range of a ship; while this contextual logic was a cool idea initially, it ended up being confusing for players. In addition, the kraken would spin wildly on occasion when attacking ships, which we affectionately referred to as “Spinning Squid Syndrome”. While this rotation was somewhat intentional (it was a workaround to avoid doing a lot more sprite animation), it definitely needed some fine tuning.

Another surprise for us was that many of the players we talked to were much more interested in sneaking around the ships than attacking them. We didn’t really reward this in the ending score screen, as we had always assumed everyone would want to attack the ships.

Tools & process

We encountered a problem with deploying the game to Github Pages. With very little time left until submission, we all vaguely thought we were doomed. Luckily, we were able to deploy straight from Visual Studio with Azure publishing, which allowed us to move forward!

Improvements for next time

Know the tools

We had never really used Tiled before, and while it was definitely helpful, it took some getting used to. Next time, we’ll use all of our development tools beforehand to gain some familiarity with them.

Test the process

In the same vein, we should have tested the entire development process on a small scale, end to end. We could have set up the code repository, ran through a sample game to test the workflow, and deployed it to make sure the entire pipeline worked before the jam started.

Work around issues with Excalibur

While discovering issues with our game engine is an important goal for us, it shouldn’t get in the way of finishing the game. The next time we encounter a show-stopping engine bug, we’ll consider changing the mechanics or creating a simple workaround rather than dropping everything to fix it. For example, we spent hours smoothing ship rotations, when we could have just had them snap to their new travel direction.

Define the scope more clearly

While we did a pretty good job of cutting features and scope from the project as we went along, it would have been better to cut those things earlier; there were several things (boss battles, different enemy types, etc.) that we still planned on implementing even when we didn’t really have any time to do so.

Add more stats

We plan on adding even more stats and analytics from now on. We could have kept track of player pathing information to see if there were any problems with the level design, or gotten more insight into the play style choices that everyone was making.

Future plans

We have been working a little bit in our free time to clean up the game code and add more features. It would be really cool to add more of our original scope back into the game now that we’re not under any time constraints. You can take a look at the latest branch of the repository to see how we’re doing.

Conclusions

  • Teamwork is key
  • Your scope is too damn big
  • Prepare your tools
  • Have an idea of where you’re going before you start

Overall, Ludum Dare 29 was an amazing experience, and we will definitely be back for another one sometime in the future.

· One min read
Erik Onarheim

We are very proud to announce Excalibur v0.2.0! There are tons of awesome new features!

Check out the full release notes on GitHub!

Release notes summary

  • Collision Map Implementation for building large static collidable levels
  • Support for redundant fallback sound sources for cross browser support
  • Particle Emitter Implementation
  • Trigger Implementation
  • Timer Implemenation
  • Camera Effects: zoom, shake
  • Polygon IDrawable
  • Alias ‘on’ and 'off’ for 'addEventListener’ and 'removeEventListener’
  • Optimized draw so only on screen elements are drawn
  • Support Scale in the x and y directions for actors
  • Added notion of collision grouping
  • New Events like 'enterviewport’, 'exitviewport’, and 'initialize’
  • Textures allow direct pixel manipulation
  • Static Logger improvements with ’.debug()’, ’.info()’, ’.warn()’ and ’.error()’
  • Added callMethod() action to actor
  • Added fade() action to actor
  • Added follow() and meet() action to actor

Installation options

  • Install with NugGet: Install-Package Excalibur
  • Install with npm: npm install excalibur
  • Install with bower: bower install excalibur