Built a daily "name the Top 10" game. 400 players in a month, but only 18% come back the next days. What should I improve?

Hey guys, I already posted about the game but I realize I forgot the most important things in that post which was the stats of the site, so im sharing here again with them Every day there's one list, the same for everyone ("Top 10 biggest countires in the world"). You get 180 seconds to name all 10. Each correct answer adds 5s; wrong guesses are free. At the end you get a share card, and a challenge link lets a friend race your run as a ghost. You can also open leagues and have a bigger scoreboard of your friends Last 30 days (pics): 407 real visitors, 97% start a game, 59% finish, 21% of finishers share. Challenge links are working: 25 sharers brought in 23 friends who finished a game. The weak spot is coming back: 7-8% play again the next day, and 10% more for more days. I'm choosing what to build next and would love your vote, but I am also quite sure it has to do with how I share it, I have instagram page for the game, but it doesnt look that good (I'll share here). Suggest your own Top 10 list (with a source), and the best ones become days A phone notification at a set time (add to home screen) (registered people get email) A hard mode: no hints, 120s Play: Top10 . Brutal feedback welcome. My page on IG