no problem!
I replayed a bit today to at least kill the first boss and I got to the third wave. The bounce down on key press didn't bother me as much this time. I think it's still worth experimenting without it, but it's not too difficult to adapt.
There's some things you could add like a main menu, a pause menu, some options, etc. In any scoring game a leaderboard is always good. In the end though you're the one who's the most apt to answer that question. Do you think it's missing something? It's your game, so you should know if you're satisfied with it.