Move the rock-eater around with the cursor.. Try to eat rocks by moving around and touching them. You can move up levels and unlock new rock-eaters. Select your rock-eater with the number keys 1-5. Note: doesn't work on tablets.
I recorded the music, so it might be a bit off-tune. Thanks to me for solving a problem with the levelling up. The levelling up is actually controlled by a hidden variable, not how many rocks you have eaten, so if you remix it that's the variable to alter if you want to change the levelling up.