LogFAQs > #980393026

People should be warned that of the 40 new levels, 14 are commentary indexes, 12 are alternate design with commentary and finally 13 are actually brand new with 16 puzzle pieces for a new frame.

from a reddit post.

i'm surprised though, because my first instinct was that all 40 must be just alternate versions (like beta designs or rejected levels or etc), so the fact that there's still actually new levels is impressive.