This is a super fun two player game! I love the workaround you came up with to have 2 players without needing to worry about multithreading!
I'll confess my dumbass forgot this was a 2 player at first and was confused at how "easy" it was - I was waiting for the "computer" to start playing and it wasn't until the screen saying "Player 2 wins" came up that I realized. This isn't a huge deal, but maybe have a P1, P2 text overlay in the uppermost corners above each team would help make this more readable.
The background music you chose was a good choice, pretty intense! The little squid game dudes at the end doing the yipee noises are adorable (I see there's no "losing" screen hehe... that wouldn't be as cute)
One thing I really like is how this isn't just about mashing the buttons faster than your opponent, because if you hit the wrong button you slip towards the void. Very clever!
Also the starting screen and restart screens are a nice little detail.
I'm excited to see this played with two people tomorrow! Awesome job guys. From rock paper scissors to this in just a few weeks, pretty impressive :)