I also thought of super buildings. Like one buildings u start with at the beggining of the game. Terrans could have an ion cannon, that shoots large blasts at the enemy base destroying everything in its blast zone. A drawback could be the attack could be hit back at u. Zerg could have like a giant form of the sunken colony, with a giant tentacle shot underground and comes up destroying something in the enemy base and could do it several times as to make it equal to other super buildings. A drawback could be the tentacle could collide with an undergound shield and be hit back doing damage to the building itself. Zerg could also have like a giant form of the spore colony, shooting a giant spore at an enemy base and haveing a plauge effect on everything it hits, killing some things. It could be hit back at u though. Protoss could have a warpgate that automatically opens rifts to anywere on the map without having to build there, usefull for transering men straight to enemy bases. But enemy units could travel through your rift also as long as its opened. Protoss could also have like a huge photon cannon, jus shoots giant energy balls at the enemy, doing severe damage. This could also be hit back. Shields could be build to defend these attacks. For terran they could have steel shields above and below ground, zerg could have organic ones, and protoss could have energy ones. These sheilds cannot last forever of course
