Green Terror is a physics-based puzzle shooter where killing aliens is your goal. The object is to aim the cannon and fire to kill the alien, whilst making sure you don't hit the human at the same time.

It's a little trickier than a simple aim-and-shoot strategy, however. Magnets pull and push fired balls around, making aiming much harder work. Hitting certain body parts on both the alien and the human is a game in itself, as the cannonball will knock a number of different limbs off their little bodies. Managing to replace the alien's head with a ball is satisfying work.

Give it a blast at Newgrounds.