Eye-catchy game!
But my brain simply can't process the matching :P
I think it would be more playable for everyone if it were rock, paper, scissors like you said, even a little kid could play it without any tutorial at all.
Regarding the help section, it'd be better if there's Next/Back buttons to navigate instead of its auto transitioning to the next image so I don't have to play it many times to get the matching.
On HTML5, you can map it to the 1 2 3 or A S D (whatever) keys for faster reactions.