Cheat Mode
At the Main Menu, press Left, Left, Right, Right, Up, Down, Left, Right, Up, Up, Down, Down. Then highlight "Cheat" option by pressing Down.
More Lives
When yo are going to another level like when you fight against clayton and you do not have lifes at all do this:
when you get into the part that shows all the levels you pass, in yellow color, go to the first level and collect as many coins as you can and get enough lifes to fight clayton.