Actually, I lost my mortar in mission 4. I sat at the end with the rocket, the annihilator (1 bar left), and a scorpion, when, to my surprise, the enemy didn't make a spider! I think the rocket and scorpion, which were on the oil refineries, might have contributed somehow, since the game only showed $30 coming from both. I quickly won the battle after that, of course. I guess that level is a sort of mind game...
Do they really need all those condors? I mean, I do need all the raptors I'm spamming in return......
Awww.... I was hoping the trap would be a "Mysterious Ally"
 "Battalion: Vengeance"){kind=icon}
 "Battalion: Ghosts"){kind=icon}