Congrats on your first game! Brings back a sense of nostalgia from doodle god games.
One thing that would make it better imo would be next to the “Discovered Combinations:” Tile adding a counter e.g.
Discovered Combinations: 10/50
It didn’t happen for me but it has happened with other games. I’m on mobile, IOS, using Brave browser, I don’t know, but i think it might be a glitch with the game or itch/browser not registering the game as closed, though that might not be it. I play the games on a separate tab with the game list still open, but even with all itch tabs closed it will still play, only when this issue happens. Hopes this helps in some way. :)
Not sure if this is intended but a few levels before 11 the stars have completely disappeared. The good thing is that the puzzles are still solvable if you can find the most common letter placement. After making the first guess the stars are displayed for the guesses. Still loving the game so far, and I like the extra challenge.
I’m on IOS mobile browser 
you shouldn’t have to re-buy it. From what i can gather from previous purchases, it’s like with steam, and console games were the initial purchase also buys future updates. If you buy a different game, for example you buy the base full version, but later want the deluxe version then you would have to buy them in full separately. I hope this helps.