Unlock Hidden Characters
The following hidden playable characters become available when you complete the indicated requirement. The four developer characters cannot be unlocked playing as Max.
Hidden above the house at the beginning of Ghost Stage 1-1.
Vertical boost above the checkpoint in Ghost Stage 2-1.
Vertical boost above the starting tunnel in Ghost Stage 3-1.
Hidden at the top of the level right at the start of Ghost Stage 4-4.
Collect 40 water sprites and 2000 golden diamonds in the normal stages.