The controls were on point, the graphics really nice. I loved the fine "grizzle" effect. The audio was really nice, but it suffered from the same problem as the whole game: there was little variation. I played until the end of day 8, my click-finger started to hurt ("must-keep-shooting!!!!" XD ), but no change in scenery or enemy. Something like a "boss" type mob at the end of each wave would have been enough....like a fat slow rabbit, that takes more than 2 shots.
Overall a really nice game and I really enjoyed playing it :)