Controls: Up arrow and Down arrow keys for moving cannon. Moving mouse to aim cannon. Left mouse button to shoot cannon. You have to kill the enemies before they get to your cannon area (brown area) You will lose a life if one goes there. If you lose all your lives then you will lose.
This is a project I made at a tech camp and I am continuing to develop at home. There are faster enemies per level and at level 4 they start to multiply. Fire rate slowly gets faster per level till level 3.