Honestly the coding's fine, I've never had any other problems with it outside of that one bug, I don't know where you heard it was bad but be careful with your sources when talking about this game and it's creator, there's tons of misinformation out there.
i take it you don't play gd anymore looool not that i can blame you this is pretty cool tho, i didn't know people played these fnaf style games in this serious/challenge-like manner. interesting content. i'm guessing it's mostly about learning the strategy of enemy AI and "gimmicks"/minigames with each game?
Yeah there's a decent sized community of people doing this stuff, in fact there's a whole ass demonlist for it. The difficulty is a bit more than just learning the strategy since a lot of them also require you to be fast and able to keep track of many things at once. There's also an RNG element but I try to avoid most of the super RNG heavy things
So imagine the demon list, but for FNAF max modes. There's 2 of them, the main list ranks stuff based entirely on skill, and the unlimited list stuff ranks based on both skill and how much RNG is required