Nice mate. I think you glazed over the fact that we're given a constant array called MORSE_CODE with these values. Not $MORSE_CODE but MORSE_CODE as it's a constant. Then it's the same from there, could have saved yourself a wee bit of time.

when I grew up playing this hand to hand with a friend or sibling, there would always be a response move:

when player 1 put out paper, and player 2 put out scissors, player 2 would literally use a snipping action on the loser's "paper"

when player 1 put out rock, and player 2 put out paper, player 2 would wrap their hand around the opponent's "rock", to cover it up

when player 1 put out scissors, and player 2 put out rock, player 2 would commit a smashing action directly on top of the "scissors"

May I add that 'technically' Rock blunts Scissors, not crushes. :P