Not bad for a first effort - could use some improvement: better control, able to buy upgrades, etc. Better then several "games" I just played! Keep up the effort!
Got to level 12 on the first try - could use improvement on the concept. The option to buy upgrades would be nice - such as faster moving mouse, or multipliers for consecutive hits without missing - moving targets, etc.
Good concept - took about 3 minutes to max out all upgrades, then boredom set in. Game would be improved by adding a way to train and improve your army, or other upgrade types.