Baba Is You - The Write Levels
3Spoiler warning for the game's secret world! Yeah it is quite late to do them, but to me, this is new content, the dev added a really secret section of 4 levels. I have only a partial savefile because I 100%'d the game around when it launched then lost the save (this probably means if any other puzzles were added between then and now, I don't know which those are).
UPDATE: Apparently you don't need to do the Level 12 trick to access the WRITE levels. Whoooops wow I am really bad. I almost got it in the unlisted videos too.
Oh and by the way trying to access these levels in the first place was really annoying for me. Here is a playlist with all the failures: https://www.youtube.com/watch?v=6YEpupcoiSw&list=PLg5Ta3CWcYX7JBhUgWzZ5fPmWj62ncX3O