Together with Half-Life 2 Valve released the game Portal. The game begins as real horror. You Wake up in an isolated room, around - the microphones and cameras, and from the loudspeaker broadcasts cool female voice. The essence of the game lies in the fact that it is necessary to solve various puzzle by means of a manual punch device, which can create two portal through which you can instantly moves. Game only works on Tegra 4, requires Android 4.3.