What games of yours were inspired by errors you encountered while working on another?

[Luke Vader]

So while working on the charging mechanic for MAD! MAD! MAD! (likely going to change that title once it releases), I stumbled upon this bug where the player progressively 'ate' the walls like it was burning through a fuse. It was quite mesmerizing to look at, so I recreated it from memory for another game.

Etr - PuzzleScript Game

I figured I'd put this excerpt from Bart Bonte's interview with Mateusz Skutnik since it fits the topic of this thread perfectly.

"Do you have an entire series planned out before you create your first chapter or do you continually expand a series?"

"No, of course not. That would actually be pointless and kind of stupid. You see, when you create a series, new ideas pop up in your head from time to time, and planning ahead would mean disregarding those ideas. We’d loose a big chunk of content and storyline this way. I create my games the same way I create my comic books. Often I start the story and don’t know where I’ll end up with it. Good example would be Daymare Town 4. Through out almost entire development I had a different ending in mind. But the game evolved in such direction that I found a new ending, the one that's better suited for the situation we were currently in. Normally a player doesn’t see that, but each game is jumping through countless parallel universes, where in each the storyline takes a different turn. My job is to float with it and steer the story in the right direction."