Damage in this game is flawed, damage rotates between tanks, meaning buying extra tanks actually decreases your damage. It should be a additive amount of all tanks you have alive instead of 1 at a time.
For the campaign mode on hard, you just have to play the game like 20 times... until you get a good enough situation... they should really make it possiable to win though, if you have to keep waiting until the enemy is super unlucky...its kinda unfair...they kill all ure resuorce makers & than just keep sending stuff to kill u while ure waiting for a turn...
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