If you liked Hitman Contracts, The Suffering, Manhunt, or Syphon filter then you will love this game, otherwise don't read any more.
I am on the Madness level of this game and it is getting intense. The sniper gun makes it a lot easier. Every level requires a significant amount of patience and stragedy. There are so many different ways to do each level that you really have to look around as you progress. I just aquired the second stage of telekinesis power and I can lift any person off the ground now and slam them to the wall to kill them.
My favorite part of this game is how you can use items with your telekinesis powers to make them float in front of an enemy then switch to your gun and shoot the object to kill multiple enemies. You really have to use as many objects around the level as you can to kill enemies.
I currently have Psi blast, charm, telekinesis(second stage), projection, Psi Pulse, and healing. It can get tough at times but this game is quickly becoming a really good game. I wont list any spoilers in case there are more people interrested in this game.