I have a couple kinda unique things to suggest. There is a small indie game called Eversion that you can find on Steam. The core mechanic is about shifting to these different planes of existence to finish levels. You can only shift at certain places and shifting opens up pathways that weren't there before. Its retro style graphics and otherwise very simple controls. The Turing Test is a puzzle game like Portal, but instead of portals, you have a gun that can be used to move energy orbs from around the rooms to unlock doors. The game feels like it encourages creative problem solving a lot more than most puzzle games. Catherine. Catherine is a game in a few styles. You spend part of the time at a diner/bar interacting with people. Then you go to sleep and in the dream world you ascend towers using moveable blocks that you must climb. Sometimes you are chased up the tower by a boss enemy. There is no combat in the game. It's about ascending the tower as fast as possible at night and progressing the story by day.