The Stanley Parable - The Stanley Parable is an Action, First-person Perspective, Puzzle-Platform, Exploration and Single-player video game created and published by Galactic Cafe.
Portal - Financial Aid Award Letter, - Messages and Calendar, - Grades.
Antichamber - "A game with half of the attention to detail and imagination Antichamber has would be a smash hit - this bare-bones first-person puzzler is one of the most thought-provoking, engaging, and challenging video games ever developed.
Narbacular Drop - Using two interconnected portals you can place on walls, ceilings and the floor, you must navigate your way through a sentient dungeon.
Q.U.B.E - Q.
GlPortal - A free open source game with teleportation.