I don't know if that was on purpose, but the noise of clicking in the space bar mach too well the sound of a camera shutter. Anyways, awesome game! Nice levels, creative idea, fun upgrades, I liked it a lot (currently trying to pass mission 10). I just don't think the graphics are as good as the game mechanics - they look a little childish, like from an educational game. That doesn't affect the gameplay by any means, it just make it less atracttive at first glance. Still, loved it!