On one about half way in, there is a level where you can get stuck. Figures it happends to me. You go down a shaft then go kill a were wolf, then I rode a shaft down and the other shaft went back up with the little pink guy, making it impossible to finish the game with out a panic button, or another way to get your friend down. Other then that I really fun simple game.
First of all, the intro is too long, I mean at least put a skip button in there. Second, frantic mode should be nearly impossible, not just very difficult, that's what extreme is for. Also there are only 10 new upgrades added to the already existing ones. Why can't you add more upgrades and this that you can do with money like in Bunny Invasion or Upgrade Complete. Other then that its about the same as the first one just with a few new features and tweaks.
Ok, now I played it though to the level where everybody is having difficulties, and then went back and fixed the bug. Though it was the second to last level feel free to replay them all, sorry for the inconvenouce. (not sure on spelling there).