Decent game, but execution of certain aspects needs some work. The way enemies spawn could be improved; rather than just having another one spawn near it immediately when one is killed, it'd probably be better to have enemies spawn on some kind of randomized timers and in randomized locations so that you'd have to act quickly and react to where they spawn. The usage of the theme is alright, though in terms of gameplay it basically just amounts to a slightly different respawn mechanic from most other games. The health mechanic is pretty interesting.