I liked the idea and the presentation, though i'd have some suggestions to improve the gameplay. The controls are a little bit floaty and the holes come at you in weird chunks, so tightening the controls up a bit would help.
Different visual states for things happening such as stopping and falling into a hole as opposed to still moving around on top of it while the game registers the game over state, or some way to show the lizards are stunned beyond them stopping moving would help the gameplay feel less like there's not much of an idea of what's going on.
For example, I thought the gun didn't do anything until I read in the description that it stuns lizards. But you definitely have the hectic bullet hell feel down without anyone firing any bullets at YOU so I have to commend that.