Barely Functional Theories

Musings on science and game design by James Furness.


A zen physics 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.

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.