Why not shoot with a mouseclick? I like that it's rather relaxing though.
Leaves a lot of room for improvement...
The graphics were alright. But the game on the whole is lacking any sort of motivational reward for killing monsters (points for unlockables/upgrades etc) leaving gamers bored only after 3 minutes of play.
Also, I find it quite annoying that the bullets/missiles continuously miss their targets.
3 stars for the effort.