Catherine

- You can't undo on hard mode, and the lower difficulties have shorter, easier puzzle stages.

- You can change the game difficulty if you're getting stuck, but only in the bar, so keep a save there.

- If you find yourself running out of lives, then you can get a pillow, then die, and repeat: on easy you get 3 lives per pillow, and on normal you get 2 per pillow.

- On easy and normal, you can reset your combo meter by hitting undo, so you can cheat your way to a perfect combo.

- Be sure to talk to everyone and encourage them, both in the bar and at the landings, if you want to help keep the other bar patrons alive. The sheep will often have some strategies for moving the blocks in the upcoming stages, too.