14FF1 - The Time Loop
When the original Final Fantasy was released, video games weren't known for having complex stories. Most games were lucky if they had a story at all. The demands on the small amount of memory that was available meant that many games had to leave their story in the manual.
Final Fantasy managed to not
only include a story, but a needlessly complex plot twist to boot.
At the beginning of the game, the first boss you will fight is an evil knight named Garland. You then go out into the world to defeat the four Elemental Fiends, that are corrupting the land. At the end of the game, it is revealed that the Fiends sent a dying Garland back in time. Garland then sent the Fiends from the past into the present. Garland transforms into the demon known as Chaos. When the main characters defeat Chaos, they are sent back to the present day. They have stopped Garland's time travelling shenanigans, but no one remembers their accomplishments.
The purpose of the entire game was to make sure that everything you did never happened.