In the recent years, many games seem to use a trope where you travel between slightly different realities to progress, either as a core mechanic or in a single level. The examples I can think of are Guacamelee (World of the Living/Dead), Titanfall 2 (past and present time) and most recently in Sayonara Wild Hearts (Parallel Worlds), which made me write this question. Is there a game that could be traced as the origin of this mechanic?
Note: I am not looking for a game where you simply travel between different realities/times as the game progresses, I specifically mean games where you quickly switch between slightly different realities to overcome an obstacle. This can be player-triggered by button press, object interaction or strictly scripted.
Best Answer
The earliest that I know of is The Legend of Zelda: A Link to the Past in 1992 on the SNES which required users to solve puzzles in the Light & Dark world to progress. Palette swapping was a common technique in video games as well as the concept of alternate realities. However, most games failed to integrate them these into core gameplay mechanics requiring players to interact simultaneously with parallel realities.