The NES release of the game contains a filter that prevents certain swear words from being used as names for the fairies. Entering any of the following names for one of the fairies will cause that fairy to blush: "SHT", "FUK", "BUM", "TIT", "SEX", "VAJ", "CNT", "POO", "NOB", "DIK".

In the NES release of the game, using the names "ICH" for Player 1 and "EAT" for Player 2 will unlock a secret level select mode called "Secret Password Mode" that can be accessed at any time during the game by pressing Select.

In the European release of the NES version, pressing Right on the logo screen for the game's publisher Storm will trigger a secret set of credits menus. This screen can also be accessed during any cutscene by pressing Right after the message at the current cutscene is displayed and the program is paused before the next cutscene screen and waiting for the input to skip it. This occurs because the input waiting routine is the same for the logo and for the cutscene waiting screens. The Japanese version of the game has no starting logo and the cutscene input logic is changed, but the credits are still in the game and can be accessed through hacking.