Tip#7: D.A.V.E. the Defender

D.A.V.E. is one of the better units in the game, especially once you unlock rockets at the Academy. Make sure you stack as many of these in your bunkers as you can - not only can these guys take and deal damage, but once you unlock rockets, they can also serve as additional A(nti)A(ircraft)!

Don't forget, the units in your bunkers that don't die in a raid will be healed! Another great reason to put the durable D.A.V.E. in there.