Although it looks a bit like Portal at first glance, Init. has its own take on the whole puzzle-room genre. You don’t have a portal gun. There aren’t any springy boots or transdimensional gloves. It’s just you and your ability to see through illusions.
According to the (brief) description on Init.’s Desura page, “Init. will test your ability to see through illusion and discover innovative and cerebral challenges that can be solved as simply as changing the way you perceive them.”
The game has an interesting look. Some have a Tron feel to them, others environments are more realistic, and others have a sketched room look. The game sells for $14.99 on the Windows PC, and there’s a free demo available so you can try it out first.