They play the Crush Ice Game, where they each take turns to spin the roulette, and must do what the roulette tells them to do (example: to knock out 2 blue blocks, reverse, knock out 1 white block, etc.). The goal is not to make the penguin in the middle fall. The one who makes it fall is the loser, and the one who loses twice first has to pour a bucket of ice water over their head, while not making a sound with the harmonica (see end of video) * Note they can make multiple hits to do what they need to do per the result of the roulette. I have also translated their 1st Q&A, which can be found in the comments of that video, or here: twitter.com/shiyuki332/status/1298600946860044291