This is quite a funny game. The gameplay is simple enough yet somehow it's quite enjoyable! The caterpillar being more and more powerful throughout the game, and even being able to defeat that giant centipede is quite satisfying yet quite scary if you think about it. The game is definitely short and sweet and I like it! Come to think about it, doesn't the caterpillar die after going into the water?
For some feedback, I'd say it's a bit unclear if you successfully hit the enemies or not, it is quite noticeable (or unnoticeable) when you and the enemy overlap and are trying to attack it. It doesn't feel like you are even firing at times.
Anyway, this is a nicely made game, good job!