Very cute, simple, and clever way to develop the theme into a gameplay loop. The lair upgrades were a nice bit of flavor to the game that I always appreciate seeing. The art for the dragon and it's animations are really nice and clean. After my first time trying, I did think that maybe I could spam all 3 keys and it was a decent strategy. Maybe some kind of punishment if you press a key a number of times without hitting/stopping an enemy? Might be an interesting way to encourage more precise use of the attacks. Overall though, I think this is an excellent entry. Well done!