Casper, is a Game Boy video game, created by Bonzai Entertainment and released by Natsume, that loosely follows the plot line of the 1995 film. The player controls Casper through multiple levels of four mini games while collecting ooze to run the Lazarus machine. It starts with the menu allowing the player to choose their difficulty setting. Then, a cut scene shows Kat and Casper going into Whipstaff Manor and then parting. After each level, a short cut scene shows Casper going to a different area of the mansion.
Each of the levels consist of four main mini games, which the player can do in any order, and two final mini games that only appear at the end of the game. However, three of the main mini games are the same every level, with their only difference being a slightly increased difficulty level. The main goal of these games are to make it to the end with as much Ooze as possible (Ooze being much like points).
Source: Wikipedia, "Casper (Game Boy)", available under the CC-BY-SA License.