The Bugs Bunny Crazy Castle (NES, Famicom Disk System)

This page details bugs of The Bugs Bunny Crazy Castle (NES, Famicom Disk System).

Bugs for the Bugs game.

Glitch Passwords#

Crazy Castle uses a fairly simple password system that encodes the stage ID byte into four characters. However, a major oversight is that the game doesn't bother to check if the resulting byte is in a valid range, allowing for many glitch passwords to exist.

The last valid stage ID is 3F; 3B and below being the 60 regular stages, and the last 4 being the game's "special levels". Entering a password beyond that range (or beating stage S1 after accessing the special levels via password) causes the game to try constructing a stage using garbage data, usually resulting in a glitchy mess that often fails to even spawn Bugs himself, thus softlocking the game.

Upon dying inside one of these stages, the game acts as if you died in a special level and attempts to send you 3 stages backwards. Because this functionality relies on a table containing which stages feature the "No Carrot" item, this also ends up pulling from garbage data, sending you to seemingly random stages until you end up within the valid stage range again.

This needs some investigation. Discuss ideas and findings on the talk page. Specifically: Someone better invested in NES reverse-engineering than me may be able to pinpoint why Roger Rabbit doesn't load garbage data. -Yoshiatom

In Roger Rabbit the results are much less severe: While the death warping issue still exists, the game will always load valid data from the game's stage set even when the ID is out of range. It's currently unknown if this is a side-effect of Roger Rabbit needing to access the FDS to load stage data, or if the game has some basic error-trapping that was lost or broken in Crazy Castle's conversion to the MMC1 mapper.

For some reason the game won't give out proper passwords for some early glitch levels, instead defaulting to the password you used to access the level. It's unknown if this was intentional or not.

A sample list of glitch passwords follows; this may or may not be moved to a Notes page in the future.