Hi there! I see you're having trouble with the Mystery Matters Puzzle Games app not loading on your Mac running OS X 10.15.7. Let's work through this together to get you back to playing.

First, could you tell me a bit more about what happens when you try to open the game? For example, does it start to load and then close, stay on a blank screen, or does nothing happen at all?

Meanwhile, here are some general steps we can try:

1. Check for system updates: Make sure your Mac’s OS is up to date. Since you're on macOS 10.15.7 (Catalina), let's verify if there are any pending updates by clicking the Apple menu > System Preferences > Software Update. Installing the latest updates can resolve compatibility issues.

2. Restart your Mac: Sometimes, a simple restart can clear up temporary glitches affecting app launches.

3. Update the game: If you installed the app through the Mac App Store, open it and check if there’s an update available for Mystery Matters. Having the latest version ensures you have the newest fixes.

4. Reinstall the game: If updating doesn’t help or you don’t see one, try deleting the game and installing it fresh from the App Store. Don’t worry, if you have internet connectivity and your progress is linked to an account, your game data should be safe.

5. Check system compatibility: Although you have macOS 10.15.7, some apps require newer OS versions. Confirm that Mystery Matters supports Catalina on Mac from the App Store description.

Give these a try and let me know how it goes. If the problem persists, we can dig deeper into logs or configurations.

Are you comfortable doing these steps? If you encounter any issues, just let me know!