Terraria is an infamous example.

I had an experience developing The Sims 1, which confirms the "Worse is Better" hypothesis, which is a harsh reality of the games industry and the software development industry in general: I pointed out to my manager that the code was shit, and we really needed to clean it up before shipping.

So he sat me down and explained: "Don, your job is TURD POLISHING. If you can just make your turd nice and shiny, we will ship it, and everybody will be happy with you, because that is what we hired you to do."

But then at least he gave me a few weeks to clean up and overhaul the worst code. The moral is be careful what you ask for, or you might have to be the one who shovels out all the shit.

https://donhopkins.com/home/TheSimsDesignDocuments/TDSEditTo...

https://donhopkins.com/home/TheSimsDesignDocuments/Comprehen...

The Simpson’s Hit & Run and Fallout 3 come to mind

There are countless great games with a lot of bugs and performance problems. Maybe most of them have pretty code behind the scenes, but I doubt it.