Play it on hardened from the beginning; you may have to fight every battle twice but you get all the achievements in one go. Strike decisively, and note you can only have 800RP at a time (= enough for a tank)
Probably the least helpful thing with this game is your accuracy so precise that bullets do not even fly from your gun to the target, but instead hit exactly where the cursor is. As KRMorben said, I'll wait til tomorrow for the Kongpanion.
 "Warfare 1944")
 "Zomgies 2")
 "Storm Ops 2")
 "Raze 2")