To get the rock costume, go to the first level, Timberdale, and enter
that one building place at the beginning. jump into one of the torches
in the middle to do a firey pulse jump. while into the air go to either
side and you will land on an edge. on one side will be an extra life and
on the other will be a white teleporter. Jump into it and you will be
teleported into the one picture. Get the red floating thingy and you
will have the rock costume.