Hello,
Just love and enjoyed playing this game. This game is quite impactful and is quite interesting to play, well done! Also, at the same point even if it's an interesting game to play, the pacing and the difficulty of the game is damn too high. It's quite impossible to go-ahead from the second wave and this is what ruins up the feel of the game. Also, you should actually introduce new things in the game one after one and give the user a space to understand the controls and the ability at first. Not just that, some starting levels with a good tutorial could work well in this case. Adjusting the flow of the game with the difficulty curve is very necessary, so have a deep look into that. However, here is an article that might help you to understand and adjust it ahead - https://www.void1gaming.com/post/flow-theory-in-game-design