play now (flash)
download source code (flixel / flash builder)

play online now (flash)
download source code (flixel/flash builder)
edit: I’d hold off playing this for now, the lovely zara notified me of some bugs :(
bugs fixed, to my knowledge. thanks for letting me know, zara

play online now (html/flash)
download source code (flixel/flash builder)

play online now (html/javascript)
Download source code (twine)

Download for Windows (20MB)
Download for Mac OSX 10.5+ (25MB)
Download Unity 3 Source code (65MB)

play online now (flash)
download source code (flixel/flash builder)

Download for Windows (31MB)
Download for OSX (37MB)
Download Source Code (Unity 3)
edit: uploaded a newer version, fixing some graphical and sound glitches, as well as a bug with one of the puzzles (that would render it either trivially solvable, or unsolvable if you went to night and back).
edit: uploaded a newer version still, fixing a couple of game logic bugs.
[ thanks to perrin, mcc, alex, and rico for testing : ) ]

play online now (unity)
download for windows
download for mac
download source code (unity 3 indie)

This requires shader model 2 support pretty much. Controls are wsad+mouse.
play online now (unity)
download for mac (osx 10.5+)
download for win

Warning, this game might be a little hardware intensive – it will look different depending on whether or not your computer has sufficiently sophisticated shader support (if the game is in an outlined style, then it’s displaying on the high-end mode).
controls are mouse + wsad/arrow keys + esc to quit.
Windows (8MB)
OSX 10.5+ (13MB)
download source code (unity 3 pro)
edited: uploaded version which fixed graphical + mouse inversion glitches on high quality modes, sorted out control issues, and added mouse sensitivity increase/decrease buttons ([ and ]), and includes a powerpc build for osx