Mistakes and Problems for the Better

[nitnit]

Sometimes mistakes or problems arise when a game is being developed that end up making a game better.

One of my favorite example is "I don't want to set the world on fire" by the Inkspots (main theme of Fallout 3) was supposed to be the main theme of Fallout 1. Due to licensing issues however, "Maybe" by the Inkspots was used instead. This song ended up being much more fitting for the story (especially the end, for anyone who's played through)


Does anyone else know of any examples of mistakes/problems in game development that ended up making things better?  

[Chaotix Bluix]

I'll have to think up about a few... though I imagine that this could also be related to glitches in a game that weren't really intended in the first place...

... like all the gitches in Pokemon Red/Blue. If the gameplay was getting repetitive for you, just the sheer number of glitches useable/exploitable could be the sole reason for playing through the games again (So like Missingno, Glitch City, fighting the normally non-combatent NPCs like Prof. Oak, ect)...