Mari0 - What happens when you mash Super Mario Bros. and Portal together?
Narbacular Drop - Using two interconnected portals you can place on walls, ceilings and the floor, you must navigate your way through a sentient dungeon.
SuperTux - SuperTux is a classic 2D jump'n run sidescroller game in a style similar to the original Super...
Quantum Conundrum - Quantum Conundrum is a First-person Perspective game with strong Sci-fi, Puzzle-Platform, and Single-player elements published by Square Enix and developed by Airtight Games.
Super Meat Boy - Let's start with what's the same: Dr. Fetus is still a jerk, gameplay is super challenging but fair, there are tight controls and great levels and you will die. a lot.
GlPortal - A free open source game with teleportation.