/vr/ - Retro Games

The one series I know the most of cool hidden shit in has to be Resident Evil.

In RE1, in the costume room there are two triggers to change costumes, but they both lead to same costume, one for each character.
The reason there are two triggers is because they were supposed to be two costumes.
The Japanese demo version of the game has a prototype of Jill's second alternate costume. For Chris the file is empty, except for a doodle of Mega Man... two of the graphics designer on RE1 later on went to work on Mega Man games.

This is also why every subsequent version/port of the game adds its own second alternate costume: the setup was already there in the game, all they had to do was make the costumes. Unlike say, the N64 version of RE2 which replaces the costumes by other ones.