A Slower Speed of Light is developed by MIT Game Lab. It’s a simple and short item-collecting game that lets the player experience what it would be like if the speed of light was slower: With every orb you collect, the “slower” the speed of light becomes and you will start experiencing what it would feel like if you walked around at relativistic speeds.
It’s a short game but it will bring motion sickness to even the strongest of stomachs and it is definitely worth a playthrough!
Available for download here: http://gamelab.mit.edu/games/a-slower-speed-of-light/, where you can also read about some of the interesting effects this game will simulate. (Warning: May cause you to lose hours on wikipedia).