Edit: The game is available now. Over here: [link]
To play the game, you need to know that 1.) The paths between rooms only open on super-loud heartbeats, every 10 or 15 seconds or so, and 2.) only paths that correspond to color-coded bosses you've killed will open at that time. So after you kill the magenta boss at the entrance, only magenta paths will open every 15 seconds. Find/kill the green boss, and the green ones will open, and so on.
I've participated in the Global Game Jam 2013. Here's an asset that was used in the game, in gif form! (The asset was not on a background but was a sprite, and so on, this is a composite of several assets for preview purposes.)
Game's called Astro Phage and will be uploaded when the game jam site stops derping.