Simple, original and fun. You respected the idea very well while keeping things simple and easy to understand. I even want more levels, that should say something ^^
Only one or two problems though : First, there are no indications about which key executes which action. I had to spend a minute trying to figure out how to activate the sword and the shield. I really like the level design, especially the one where you had to jump, slash the robot, and then jump again to reach the exit. But that one also asked having good reflexes, so be careful with that.
With that said, I'm really impressed. You should keep developing this game and upload it on Newgrounds, I'm sure you would gain high score really quickly. Nice job ;)