When talking about compatibility, first thing to keep in mind is that The Sims Mobile is a big game. We understand it's frustrating to find out your device is not compatible, and even when we have done our best to make it compatible with as many devices as possible while building all the features, unfortunately it won't run on every device.

With thousands of different Android devices, compatibility is not a simple matter, but fortunately Google Play will let you know if your device is compatible or not.

Things to keep in mind:

You will need enough free space in your device to download the app. If you don't have enough space, Google Play might tell you your device is not compatible. Please, make sure you have at least 500MB of free space when trying to download. Also, please, keep in mind the app might require more space in the future.
Make sure your Android and Google Play Store app are up to date.
You can take a look to this article to learn how to check if you are running the latest Android version.
In Settings -> Display -> Screen Resolution, make sure you are running at FHD+ or WQHD+ resolution (not HD+ resolution).
To make sure there's not an issue with Google Play Store app, in Settings -> Apps -> Google Play Store -> Storage, tap Clear Data. Reboot your device, open Google Play Store, accept the Terms of service and try again.
If you have other devices in your Google account, you can check compatibility with all of them at the same time from Google Play website: https://play.google.com/store/apps/details?id=com.ea.gp.simsmobile&hl=en

If after trying all these steps Google Play is still telling you your device is not compatible, unfortunately, it won't be possible to download the game