Thank you for playing and for the constructive feedback! There aren’t many multiplayer one-button games, so I’m pleased I managed to just get that working, though I agree the instructions could be clearer.
I think a more arcade-like “Player 2: Press any button to join!” flashing prompt could help avoid accidentally triggering 2-player mode. It is just semi transparent currently. I could also make Space/Enter work as expected or not at all but still allow you confirm with the smack button. Something to think about for sure.
I also like your idea about the starting ticks. I think I could have made it easier to tell where the half way point is visually by having the balloon leave the screen at the top too, Thanks again for the thoughtful feedback!