Great, but level-ending glitches.
Overall, this is a great game. You end up customizing your tanks with everything in mind, and even can make in-combat modifications when you screw up badly. There's just so many glitches! Sometimes your tank goes invisible, or unequipable. Sometimes your weapons just stop shooting altogether. There's got a few levels I can't even hope to beat because none of my guns, though powered, work.
Then there's the "use me!" levels. Sure, they're a great extra tutorial to help you get to grips with the uses of each person. Until the last battle with the saboteur brothers, which took me five minutes of them running to the tank, hitting it once, and the engineer knocking them away. A cooldown for knock-aways would have saved me a fair bit of time.
Those are my only gripes. The rest, pure gold. Keep up the overall great work.