Who doesn't love ninjas? With their stealthy black masks and lighting quick reflexes, it's hard to resist a cool game with them on especially if it's offered for free. Take NinJump HD for instance. This stunning and fast paced game puts you in control of this masked, sword wielding hero. Your main task is simple, you just have to climb a wall as high up as you can go. Despite the simple gameplay, the game is one that's hard to put down. It was developed by Backflip Studios, a company who seems to have a knack for making even the simplest, most mundane game premises quite addictive. They're the same geniuses who gave us Paper Toss: World Tour and Ragdoll Blaster 2.