What a pleasant, yet challenging arcade game. Focusing on the switches is harder than it seems!
I really like the percussive sounds of the switches and creatures. Gameplay began to sound like a drum beat. It was funky stuff.
As far as I'm able to tell, there is no reason to turn the red switch off. It's below the other two, so turning on either blue or green blocks it. You can't let creatures go past the red laser anyway; just leaving it on means you only have to juggle two switches.
Anyhow, good job!