Thank you for the kind words and the suggestion. I am happy to be of service in brain-breaking :)
I did consider having an indication of whether you need to win/lose at some point in the development (for example, by changing the background color to red when you need to lose), but I find it more enjoyable (and easier to get in "the zone") to not have that, so this was the version I ended up with. If I had more time (and more experience with coding), I would probably have added in the option to choose whether or not to have the changing background, a random win/lose mode with the changing background, and the option to reorder rock/paper/scissors.