Casper

Casper is a handheld action-adventure game based on the boy ghost of the same name. It is one of few video games in which Casper can actually go through walls, though only through the ones within each level. It's up to Casper to help safely guide him through each of five levels using various transformations and objects to help the zombie Doctor collect flasks with the formula to cure him. There also six children in each level to rescue, though the player does not need to in order to finish a level.