Asteroids Extended (js13kGames 2021)

As every year since 2017 I started work on a small video game in August. The annual js13kgames game jam calls for a JavaScript game that fits within a 13 kilobytes ZIP archive. The contest runs from 13th August to 13th September.

For the first time I brainstormed ideas for a game with a friend. A few years back he had started a tank game that only used vector graphics. This imitated the style of early games using an oscilloscope to draw lines on a display.


A week into the project we noticed that the theme of the jam wasn’t “Decentralized” which would have allowed for a tank game. This year’s theme was Space so we had the change our direction. Sadly, this meant that our vector graphics wasn’t going to be unique. Even the official example of the jam was a clone of Asteroids which is the most famous game using this visual style.

Nevertheless, we decided on building an Asteroids clone as we had plenty ideas on how to expand on the base game. We wanted to implement planets with gravity to land on, race tracks to compete against the clock and AI spaceships, a multiplayer and more.

For the initial idea of a tank game I had written a basic AI for driving a tank to a set location. The same code worked very well for the spaceships. Based on its location the AI would press inputs the same way a human controls their spaceship. I ended up not using AI-controlled ships as it would have needed another AI to plan a route or fulfill a more complex goal.

In the end, the planets are the only extension which made it into the jam submission. It’s hard balancing a full-time job, a personal life and multiple hobby projects – one of which is a video game trying to expand on a video game classic. I hope you enjoy it! 😉

Play Asteroids Extended