I played the two first levels.
Too bad we can't play more, there seems to even be a generation or warp system as you don't get the same levels on replay.
Everything about what's playable is very cool. The game looks specially good and the intro and intro music are super nice. The game is very pleasant to control partly due to engaging sound effects. Finally everything about how it plays make it feel like a NES game despite the, as far as I'm aware, anachronistic genre which is fine, the overall look and sounds, the actual tower and enemy sprites, the speed and the amount of things which happen on the screen.