Subtract Space

Each attacking unit is assigned a number that represents its strength. Taking out the unit involves hitting it until its number goes down to nicely round 0!

To do that, you are given the best weapon of all: the Substractinator! This weapon of Math destruction shoots substract-o-spheres which bounces off of shapes. Use this power cleverly and you might be able to hold off the S.H.A.P.E.s' attack.