its verey funny how in timattack, you choose a most advanced model (which is locked) and finish the game, the image shows up then disappears if you come back again!
in survival, from wave 20 at least two of my characters died but they revived and revived and revived. I used eldritch eldris (spelling error or what) from conjuror, inspire from knight, purify (a lot of times repeated) from cleric, flickering flames (individually) from mage because all those skills says until the reamainder of the battle. that means until you die! in survival, "until the reamainder of the battle" is more effective than in using them in campaign .
oh, just got the surviving achievement! it is not so easy but you just use drop weapon to the edge of the screen whenever you get a weapon enemies easily block/dodge, or range weapons. (specially in high levels, don't use any range weapons, even sniper. just use dark energy and press Z everytime enemy is next to you or farmer's spike and press X)
I go to da red team, select basher, then fully upgrade hp shells then overload. no ap shells as possible! I kill people with overload, then towers with overload. don't move as possible. its da best way to win! xD: plz thumb up if it works. I NEVER lost with it!!