Some chambers in the mappack are a bit so-so and even if they have interesting parts, aren't that special, but chambers 17, 18 and 19 get better and better until 20 is just an all-arround gem. It incorporates so many of the best no-elements mechanics into one pretty much perfect package of a puzzle. Nicely done! I'm adding this one to favorites.

My walkthrough .

good fun, the last portal was a little tough to hit. cheers