this is not impressive at all, it's actually made in penguinmod and uses a few custom extensions, so shame on the person who made this.
Viewing post in Portal 2D + Chamber Creator comments
Yeah, so? They still made it in a VERY limiting game engine and they still made it themselves. How about you remake this with the same tools this dev used. And even if you finish it and its just as good as this, how long did it take? Probably a lot. How about shame on you for undermining someone's work like this?