Very nice game, I can imagine myself playing this kind of game on my phone for hours! The music was very fitting and the movement smooth. One thing you could consider is to have it turn to the left at some point, now it feels like I'm going in almost a "circle" as it keeps slightly turning to the right, or the flags are coming from the right. This made me a little bit dizzy.
But other than that, I thought it was very enjoyable! :D
I don't know if you've heard of Game Development World Championship before (gdwc2019) but it's a competition for indie game developers where they can submit their games and it's free! It's great if you want some more visibility for the game and it only takes a couple of minutes to join :)