Take control of the biters and lead them to victory against the invading engineers.
Mods introducing new content into the game.
Changes to enemies or entirely new enemies to deal with.
For anyone looking for an updated version of this, search for Mitchplay1's version (Hive_Mind_MitchPlay). It even has support for a lot of custom biters and SE. It took me an embarrassing amount of time to realize there was a remake of this mod.