"Duality": I'm not sure if it's intended but it worked out.
"Gomen ne sunao ja nakute": Here the stairs just worked out with stretching and stuff. It was quite precise and tight. Not even sure if it depends on the new builder physics.
"I TOLD YOU ABOUT STAIRS BRO": I needed longer to solve this level than I should since the solution is actually not that hard.
"Lix Ferenda": I have nothing particular here. It has some (precision) parts that you have to think in advance of, which can get nasty.
"Round Trip": This level was a breather.
"Segmentation Fault": It somehow felt so mean to abandon that one hatch completely.
"The Ring of Fnargl": This led me in the completely wrong direction at first. It's a really peculiar level, almost Vicious worthy.
"This is a Stickup": This felt like a rather finicky level and I focussed the wrong side at first. In the end it was extremely tight and I don't know if what I did is intended.
"Merge Sort": For this level I had an indirect hint since I've glanced through the community set replacement thread sometime. Simon said there:
Merge Sort: rank 3 -> rank 4. Or put more steel, to point out where you should not mine.
Ironically in some way the level actually tells you where to mine but you have to understand it at first. But nevertheless this level feels quite obscure, especially since you see the whole crowd only very late. The positive aspect is that you learn a mechanics but on the other hand you can get deeply stuck in this level.