Barely Functional Theories

Musings on science and game design by James Furness.


A zen physics mobile game of orbital mechanics and space exploration.
1.07 MB download required.


It’s all explained in game, so feel free to dive right in!

Click and drag to aim a probe and release to launch it. Clicking anywhere once a probe is in flight will freeze it in place, allowing you to relaunch from that point. Clicking and dragging whilst a probe is in flight will fire the probe’s engines mid-flight, accelerating the probe.

Scan the planets and destroy the space mines to proceed. Every level can be cleared with a single launch push!

In case you want to… Reset Save.


Probus stands as my second serious HTML canvas game project and the first that I have been happy to call complete. It was developed during the final year of my PhD during the sparse moments of downtime that I found myself with energy.

This game was heavily inspired by the excellent Desert Golfing by Captain Games. I really love its low commitment play style and the sense of exploration created by the small discoveries made along the way. I tried to add some of this feel to Probus with some hidden extras to stumble across.

Mobile Release

Probus was primarily designed as a full-screen mobile application and was developed as an HTML canvas simply because I’m comfortable with the environment and didn’t want to learn a new system at this time. I was originally hoping to bundle the canvas into a mobile app using CocoonJS. This tech advertises a fast full-screen canvas implementation for an easy port to a ‘native’ mobile app. Sadly, at the time of writing, this conversion has not been a simple as advertised and the asset loading routines don’t play nice with my pre-loader code. For now I am exploring other canvas to app solutions, though I am fearful of the performance costs these may entail. I still hope for a mobile release in the near future as I think the game is far more suited to this environment.

Tools and Libraries

This game was developed entirely using free software,

  • GIMP to draw all sprites and particles.
  • Sunvox for sound effect production.
  • EaselJS, SoundJS and PreloadJS from the CreateJS suite for convenient wrappers to the native canvas functions.

I have made the code available here for anyone who wants to poke around in it. It’s not particularly pretty, there’s certainly parts I’d redesign but I’m happy with the end result.

Probus is Copyright (C) 2016 James Furness – All Rights Reserved
James Furness has asserted his right under the Copyright, Designs and Patents Act, 1988, to be identified as the author of this work.