Hah, that description kind of reminds me of Gunz, where some bugs in the game lead to players being able to climb walls, basically fly around and attack rapidly while moving.

Here's a timestamp in a video that talks about it: https://youtu.be/zvC67kmYxPA?t=82

Though it was a third person game. Imagine creating an entire way of playing a game because of bugs in your code, though.