Carnaugh: Anyone else have an issue with the third Rimtech mission? I completely wiped out all units, on all three layers, but I keep failing the "eliminate enemies" bonus objective. I scoured the map for any tiny spot, for any enemy recon pole, and even set hoverjets all over the place on patrol. My underground layer is flooded with recon poles to reveal all parts of the underground and surface layers.
Some of the subterrainian recon polls report an enemy on the surface, but I can't see what they're seeing. Unless they're crying over the objective building, but that's indestructable.

Cerbykins: If this is the mission I think it is, and the objective is the alien artifact, you can nab that with the drill truck and take it out of their hands.
Can't say for sure that will solve it for you, but I definitely took the artifact and I got credit.

Cerbykins: ...yeah, it is this one. Bonus credit for eliminating all enemies. If you get close to the structure, a 20-minute timer starts and you need to survive, but you can clear everything and get full credit. The Hedoth structure is still enemy-owned, though - so it probably needs you to send the drill truck over to cap it ('invade').