The Ninja live in hiding in an underground lair, hiding from the plotting samurai. You are an apprentice training to be a good ninja. Use right and left to move. Press down to roll. Press up to jump. Jump to a pole to swing. Jump to a rope to swing kick. Run up to a pole or spear to vault slam. Run to a rope to swing. (The third scene, when you chase the leader is a race. Hold down right to beat the samurai leader across the dining hall. You can tell you won if the samurai stops running and starts talking.) Save the ninja!
The idea for the name came from a game my friends told me about called Pirate 101. The idea for a ninja apprentice game came from the name. The samurai came from books I read.