This is just a small head's up (I intend to do a larger discussion later) about one of the most awesome and geeky indie-games available at the moment: SpaceChem by Zachatronics Industries.

The basic premise behind SpaceChem is chemical engineering: in each assignment, you get some input molecules and you have to turn them into the requested output molecules via bonding and unbonding their atoms, and the occasional nuclear fusion. A simple (and decidedly sub-optimal) example:

The chemistry part is just a front, though. What the game really is, is a programming simulator. You have a tiny board (10×8) board with input and output zones and two 'waldos' that trace a path on which you place and execute instructions: basically a tiny dual-threaded CPU with a select instruction set. I know it sounds simple, and that's exactly right: it sounds simple. However, working out a workable design hard, VERY hard. Especially when you try to optimize a design for least time or components.

There are in-game leaderboards, showing you how much a design that you have toiled away at for hours actually sucks sweaty donkey balls, and a more detailed scoreboard at spacechem.net. You can also upload your solutions to youtube. Here's one of mine for “Gas Works Park”, where you turn some random carbon strings (C₃ / C₄) and water (H₂O) and turn them into methane (CH₄) and carbondioxide (CO₂). Solution details can be found in the video description.

• Publisher site (with other engineering games): Zachatronics Industries
• Game site: http://www.spacechemthegame.com/
• Review: http://www.rockpapershotgun.com/2011/01/10/wot-i-think-spacechem

If you like programming and games (which probably describes readers here pretty well), you need to give this a try.