The controls might have been better if ...
... you got rid of the space bar to jump. The mechanism to move the ninja from one side of the rope to the other is through the arrow keys, and it would seem that moving him from one rope to the next is just an extension of that. That is, the horizontal arrow keys should naturally take care of ALL horizontal movement. Unless there is a good reason to break that movement up into 2 separate keys, you've only added additional burden to the player as he now has to get used to unfamiliar game play.