Playable!(ish)

Clicky

Please note, that this is an OS X app. So if you don't have a mac, it probably won't run. Instructions are easy. You're the light. Destroy the darkness. There are no keys, no buttons, none of this messy 'input' garbage. Just move the mouse over where you want to influence and it'll grow faster than the rest.

You might also need the sdl runtime junk from here.