How do I setup time limit for gmes in the apple tv?

You may set Restrictions for content and third party apps,

but time limits (“Screen Time”) are currently not for the Apple TV box.

You may send Apple your suggestions for future versions tvOS:

Feedback - Apple TV - Apple

Hi A1van,

Are you looking for steps to restrict certain content on Apple TV? If so, follow these steps: Restrict access to content on Apple TV

1. Open Settings Settings on Apple TV.

2. Go to General > Restrictions, turn on restrictions, and enter a 4-digit passcode.

Once you enter and verify the passcode, restrictions and other options in the Restrictions menu are enabled.

Configure what types of content are restricted

1. Open Settings Settings on Apple TV.

2. Go to General > Restrictions, and enter the passcode if required.

3. Select options to restrict iTunes Store purchases and rentals, allowed content types, Game Center settings, and other settings.

You must first turn on restrictions to configure the Restrictions settings. To access restricted content, you must enter the passcode each time.

Best regards.