Very charming.I was a bit confused when the arrow keys/wasd didn't seem to move the hands as per the instructions. However, the game really didn't need anything other than the timing of pressing space to be engaging and fun.
Yeah, the player controlled hand movement is not that noticeable und the 'shaking' , that would have needed a bit of an indicator for sure.
It is, as you said, also not that important to do, it only helps a bit to align the hand shaking a bit more.^^