Very cute game! I love the visuals and the gameplay! Music is also fitting with the game.
It's just a minor thing and I don't know it it is easy to fix on unity or not, but it bugged my eye that the nightmare clouds that are in front of the cat are rendered behind them.
The sound the big nightmare does before throwing a missile are very fitting and help play a lot!
Also, I miss a guide or something; you end up getting pretty well how it works but at fist I didnt know what the doors where, I though it was a level selection screen instead of a random power up for the next level; and also, I didnt get to know what the doble arrows power up does, and the other ones I only realiced after choosing them (except for the heart one).
I said a lot of criticism here but It also means I like the game a lot, I just played enough to form a deeper opinion, sorry if its too harsh but you did a really good job here, congrats! :)