Board Thread:Questions and Answers/@comment-24926745-20160214213230/@comment-27701762-20160215203803

RagingReshiram wrote: i did get the "let's get this over with" line, but even then, the fight never happened. Right. It's not supposed to happen. You only get to fight Omega Flowey once.

If what you're trying to accomplish is simply to refight Omega Flowey, then you'll have to do one of two things:

1) Complete a True Pacifist run and do a True Reset (NB: it's possible that doing a simple reset would solve everything, but I am roughly 98% sure that won't solve the problem).

2) Mess with the undertale.ini file to essentially undo the progress. I'm not sure exactly what you would need to do, though. My guess is mess with the [FFFFF] lines and remove the "TALE" and "won" lines under [General]. If you're going to take this route, create a backup of the file somewhere else. It's possible you could find more information elsewhere about what the file should look like.

If you ever want to get to redo a particular part of the game, especially when getting to those parts is long or tedious (boss fights, specific puzzles, etc.), then you should get to the save point just before, save, exit the game, and copy the files to another folder (I have a folder of Undertale saves with various backups like this). You can then switch out the files as you please.