When you get the boomerangs, throw up to 3 of them in the air, then switch turtles, and have the new turtle catch them. The new turtle will be able to use those boomerangs without having picked up a boomerang icon.

Find a doorway that has a pizza slice or full pizza right at the beginning. Enter, grab the pizza, and exit. If you go back in the pizza will regenerate. Use this to restore power to all your turtles.

Hop in the Party Wagon on the 3rd level. Whenever you see a Crusher nearby, press SELECT. You will exit the car, and the Crusher will disappear.

The Giant Mouser at the end of level 4 can be beaten even more easily than normal with this trick. Just stand under him and wait for his mouth to open. When his mouth opens to reveal the "weak spot", pause the game. Unpause the game, and the Mouser's mouth will be closed again, but his weak spot will be slightly visible from behind his mouth. You can now hit it to cause damage while his mouth is closed! Repeat this every time he opens his mouth for an easy victory.