Max out defence and the enemy will do 0 damage. Max out counter and you'll reflect even more damage than what's done to you. Thanks to these I could defeat the boss quite easily but it was a long battle.
challenge maps are so bugged, mostly the things that propel the pixels really fast and destroy everything in its path... almost impossible to beat one of the levels, and keeps launching pixels in random directions and ******* everything up
 "BioGems"){kind=icon}
 "Pixel Legions"){kind=icon}
 "Necronator"){kind=icon}