Would be nice to be able to suicide a unit (trebs). I find myself wanting to kill a lesser unit that isn't upgraded or a treb after it's served it's purpose and is so far behind it's now useless.
Easiest way I found was use cash generators and upgrade your drones *entirely* Then just teleport back and forth to keep your villain safe. 1 play through to get all of the achievements.
 "Takeover"){kind=icon}
 "Kill the Heroes"){kind=icon}