well it's possibe to get 100%. there are two rooms which are probably harder to find: one is a room in mint end which is not connected to the map (if you got all love letters you got this one) and the other is the dev room.
i think the black chest room isn't connected to the map either...
the big human statues are things from the game world.
That said, I'm confused about the seal business. It says that "certain blocks can be broken by the seal" and then presents me with yellow blocks. However, earlier yellow blocks, if I backtrack, cannot be broken by the seal thingie. Why not?
there are two different yellow blocks; one is like a mother yellow block which starts the chain reaction.
Forgot to say: sometimes I stuck inside walls after dashing if game slows down in that moment
this is a very rare bug which i never got around to fix, haha. i'm sorry for that. i didn't think it would happen to anyone!