the FINAL, final boss (Epic) is a pain. Use darkness charge (in the purple in-battle warps) to charge your energy. Then use the time stop and the healing at the same time. Repeat (the entire time have auto fire on)
I give it a 4, everything is great, but the targeting system is off and at times, i'd really like to be able to specify in which general area to shoot. I prefer how bloons TD 3 gives the option of targeting like 'first, last, far, near' etc.
try to end up with 2 level 3 machine guns on each floor. each floor having a lazor. 2 floors lazor level 3. and the rest level 2 lazor. move the elevators as needed. i beat the game using it.