Keep going back to the giant face, he tells you the name of the level that you need to explore.
You have to explore the level until you find the right chest. Each level has 4 chests: Gray, Red, Blue, Green. (Not all chests are needed)
Chests/treasures unlock new abilities (ex: ground pound...
Wario Land always had minigames that play different from the main game, except maybe Shake It. I can't remember if Shake It had any. My idea is to have Mona be playable for these sections, She would unlock coins/treasure/lives/keys that would help Wario on his adventure.
Another idea is to...