Bubsy in Claws Encounters of the Furred Kind
Bubsy in Claws Encounters of the Furred Kind
When the Japanese version's passwords are put together in a string, they make up the first 114 digits of pi.
(3.14159265358979323846264338327950288419716939937510582097494459230781640628620899862803482534211706798214808651328)

The PAL and NTSC versions of the game use vowels instead of numbers, and are made of random strings.
Contributed by Dazz
There's a hidden credit line in the game's ROM which reads:
(C) 1992 Basement Boys Software

Basement Boys Software were a group famous for making hacking tools on the Commodore 64 in the late 80s, who had some members go on to Chip Level Designs, a company that used to provide sound programming for a number of SNES titles. The same credit appears in Cool Spot.
Contributed by Dazz