tl;dr: Tentacles. Thank me later.

Or in more detail: Unlock the squid freak early. The tentacles are amazing, on "hard" he even gets two of the tentacled claws. You want to have water going in the claw machine if possible, which should be easy. The squid comes with a water bottle and it can be grabbed easily. Get the lava ball if you can, turn water to lava. You'll be dishing out so many burning cotton balls (and weapons and whatnot), it's easy mode.