Love the idea and the hand drawn style, but I felt it needs a bit of fine tuning. I think having the main weapon on a counter with cool-down is a bit harsh in the later waves when it takes multiple shots to take down the enemies with shields and the bullets fired at you simultaneously. Often found myself out of shots waiting for them to replenish when I got killed. With some fine tuning though and a bit more time this could be sorted out to make a great little game.