When the title screen appears, select Option. Then simultaneously press A
and B on Controller Two. You will now have a level select and two new
difficulties (Mania and Very Easy). You will also be able to increase the
number of lives to nine. (The game itself reveals this trick when you finish
it on the hardest level, but you can use it at any time.)
On the title screen, push Right and B on Controller One and Left and A on
Controller Two. Then with everything held Down press C on Controller Two.
Now just select two players and both players can pick the same character.
Unfortunately, they will both be the same color, so it can be confusing.
