Tri: Of Friendship and Madness (2014)

TRI is a first-person puzzle exploration adventure game where you place corner points onto walls to build walkable triangular platforms. Find a way through the towers and dungeons in sophisticated levels. Solve puzzles, climb vertiginous abysses, reflect light-rays and try not to lose your mind when you're falling upside-down. Don't worry - the TRIs will let you create your own paths in this mystical world.