Level (Portal 2) - The Bounce
This level is all about the speed and jump paint types, with two particular big "set pieces" of bouncing. Hence, it's called "The Bounce." Both types of paint come in handy throughout this level and there is a fair degree of openness about the order in which you construct your solution. The core of the puzzle is fiendish indeed, but the solution will have you soaring with delight.
I had learned so much about building a first-person puzzle from making the first two of my Portal 2 levels, but I knew for my third that I wanted to branch out to some of my favorite mechanics of the main game. Building the two jumps took a surprising amount of time, and a working solution only happened within the quarter of the work.
But I stuck to the concept for the jumps, despite a hell of a lot of polish on look and feel, and am really happy to see that the idea was possible and it's really fun to think out these elaborate movement sequences in game. Experimenting with the paint and iterating on ideas for solutions (hey sometimes I forget my own designs) gets to the core of first-person puzzling and is super satisfying to play and design for.