Control our little hero with your mighty finger taps to jump over moving sawblades and spikes, swing a deadly katana sword in faces of annoying imps, time your strikes right to block demon axe-hammers and knock them back to the fires of the hell they came from. Don’t forget to throw your shuriken stars to get rid of fireballs and ranged enemies. Be aware of sneaky jumping headcrabs and dodge them before they stick to the little ninja character and pull it down to the danger.
Master all the deadly ninja skills, snipe enemies from a distance, push them to the spikes, do whatever it takes to survive longest in the endless level and kill most enemies, so you can power your way to the top of leaderboards and prove your friends that you sure can do it.
Or get on the challenge level, where a reward awaits at the end of your journey, die a lot, get angry, rage, memorize trap positions, make rewarding dodges, don’t take the easy routes (that’s not what ninjas do) and beat it. Beat it before your friends do.