How did they end up here?
Think smart: these users are your target audience too.
Why are they playing this particular game?
How do they decide which game to start playing: app store reviews, YouTube testimonials, game review sites, ads, links from other games, what?
If you can figure out where they "live", perhaps you can design a better marketing and acquisition campaign to target them for your own game.
Why do they prefer this app?
What is it that they find most interesting in the game they are playing? What feature are they most fond of? Which game mode do they like: one-to-one, solo or team play?
How important is being part of a group, a clan or alliance?
What, if any, ads do they like?
Do they go all out and buy any new weapons/upgrades/features available for their clan or game?
What is it that keeps them coming back to the game again and again?
What do they hate in the app, what would they like to see next?
Finding out what frustrates or drives users away from a competitor's game is information everyone would love to have.
Most of the time, game developers themselves are not sure if a new feature will be a success until released.
Imagine you knowing this before you even get started!
Feedback on your app icon, title or video trailer from your competitor's users
Think practically: your competitor's users are your target audience.
What if you could test your game concepts, logos, titles or even app trailers and make a better decision based on information straight from the actual users you will be targeting?
Better decisions that can help you attract that target audience from your competitor?