The visuals and animations are very polished and well-done. Having to memorize the sequence of doors is an interesting take on the theme and a good twist on this style of game. I like the ricocheting bullets and the nod to Zelda. I think it was a good idea to have the recoil mechanic as it discourages the player from simply standing in a doorway and firing at the enemies. Doing so could send them recoiling back into the wrong room and mess up the door sequence if they're not careful with it.
The aiming mechanics seem to be a bit off. There was quite a few times where I had the reticle directly on a non-mobile ninja, but the bullet would go right past the enemy anyway.
I could see this one being expanded on with more weapons, more enemies, and even more door patterns. Nice job!