The Spherebots float above the doors in the corridors between chambers. As long as they live the doors will be shut; the player must take control of the Dog and go into space to destroy them and open the path. The Spherebots attack with waves of projectiles, but do little damage. A single charged attack from the dog should be enough to destroy them.
Unlike other enemies, Spherebots don't respawn. While their sprite may appear intact on leaving and returning, it is a glitch; they do not attack, the doors below them remain open, and they will revert to their destroyed animation in one attack.
The player doesn't get much experience or money for fighting the Spherebots, but then that's not the point of having to kill them.