Yeah, overwriting the float cake is a special case because you need to have SOME means of attacking a boss for the fight to be possible (I forgot about that, it's been 6 years...)
The chains are supposed to indicate chandeliers (every chandelier has chains and there's no troll chains that just end in the middle of nowhere)
Frozen enemies instantly shatter and die when hit by melee attacks, though you'd need to either be in multiplayer or have a reserve whip to hotswap to in order to do this. (They also don't become solid if the player is partially inside them upon creation so if you're close enough you can slip through them, but it's hard to do that without being in contact damage range...)
I'll add "faster screen scrolling" and "tells for Icon of Sin" to the todo list. When refamiliaring myself to the game I also noticed its divekick attack has like zero warning so that'll also need some tweaks.
(So far a lot of the things you've suggested have been fixed and I've started to chip away at the compatibility issues)
