theme: it's simple, not bad, the name said it all.
Polish: I like the screen shake and sound effect, but the game does miss some polish.
art: I like the art of the game, especially the tree; they add a lot to the feel.
Concept: It's a simple concept, pretty sure it would be more fun if you added things like upgrades or different enemies.
enjoyment: the gameplay was simple, not bad for a 1 week gameja,m but with time, adding things like different weapons, enemies, upgrades, the game would become really fun.