Nice game again I liked to go through the 20 waves trying to guess what the next enemy was going to look like,but here is my critique :
-I think you could have made harder enemies in another way than just making them more resistant,for example you could have made them faster,bigger,or you could have added shooting enemies,etc...
-The game is a super easy,even in hard I just felt like they were just a bit faster than usual.
When you've obtained each power up it's super easy to just slice through waves of enemies no matter how resistant they are.
-When you've reached wave 20 it just loops infinitly,I think you could have just made a You Win screen or something of the sort. After wave 20 you've seen everything the game has to offer and then it gets uninteresting pretty quickly aftewards,the player needs to know when to stop.
But overall the game was fun,I had a good time,not really memorable but very fun.
I'll wait for your next game then ! Keep improving !
ℌ𝔏