I will say if you're new to RTS's do not try brutal mode unless you want your face smeared across the ground then stomped on.
Holy cow u have no idea how long it took to get that quote above. These smart phones are awesome but they need major help selecting text and copying and pasting.
Anyway, when you play this game on hard or brutal do the tactics change from the enemies or do they just rush more units? They don't handicap your units and call that hard mode? What changes on the harder modes exactly?