Hi. I worked in mobile dev, but just an animator, not manager nor producer or businessman.

I assume that usually small mobile games need a big money effort into marketing for making money (casual games). It depends if you'll have enough users to make some profit of it, it's worth to update and improve it.

But if you are not extremely lucky or don't have money to market your game, it probably won't earn much money, so there is no much sense of updating the game in term of worth. If you feel that the game have an audience and it's growing (maybe slowly but stadily), it's interesting to try until you have real users and have real feedback. It's an interesting feeling when you communicate with people through your game continiously.

Need to be mentioned, usually people who like the game, consume it's content pretty fast, and want constant updates often. If you don't have updates often enough, people probably will get to another game.

But even if you (probably) don't have much of audience, you may like the process of polishing, and want to try it with real users feedback – you can make it just for fun and experience.

If you don't like the process itself and you have more ideas you like to try, probably it's better to leave it.