In this use case, you can customize your app for each user, choosing the right
level of difficulty to fully engage each individual user with varying levels
of player skill. You can use `level_difficulty` as a Remote Config
parameter and user engagement as an objective. Add any additional metric you
find relevant here --- this example uses `level_complete` to gain insight
into user progression through the game.

You can also use an objective like ad impression revenue (as configured in
[Optimize for ad impression revenue](https://firebase.google.com/docs/remote-config/personalization/use-cases/optimize-ad-revenue.md.txt)) or
use `in_app_purchase` to optimize for in-app purchases.

| **Personalization component** | **Potential or recommended values** |
|---|---|
| Remote Config parameter | `level_difficulty` |
| Alternative values | `easy, medium, difficult, impossible` |
| Objective | `user_engagement` |
| Additional metrics | `level_complete` |