World Flag Challenge app — what would make this actually addictive/useful

I built an app to test how well you know world flags. What it is: A fast flag-identification challenge (speed + accuracy). Why I made it: I wanted something lightweight and “one more try” addictive — curious what people think or if any suggestions Try it here: https://www.worldflag.infy.uk What I’d love your input on: Would you recommend it? What would make you come back tomorrow? Any tweaks that would make it feel more professional try it out, have fun!