In my opinion, the developer had too high expectations, if you create your first game and want so much money right away, you just make a big mistake right from the start....
When taking the risk of creating a game, you have to be aware of various problems, if you have come this far, players like your game, but you as a developer for various reasons cannot continue creating the game, the only option apart from abandoning it is to simply sell the copyrights, players still will be able to play the game and the creator will earn some money.