This is one of my all time favorite games for the PC. Its called PORTAL. Its a simulation where you have to get to the end by solving these teleportation problems. You get a gun that can create portals, a blue one and an orange one. You go in one and exit out the other. For example, if you need to get over a moat of acid, you just fire your gun at a wall on the far side and another one on a wall near you. Then enter the portal near you and you come out on the far bank. The levels keep getting more and more complex requiring you to utilize your momentum going thru a portal to ‘fling’ yourself. It was very challenging and I only had to go to the web twice because I was stuck. The song at the end is very cute. Someone even made a video with it.