If you're looking for a game app development company, there are several options to consider, you can go with
Toptal: Toptal is a network of highly-skilled freelance software developers, including game app developers, that work with clients worldwide. You can search for game app development companies on their platform and browse their portfolios and reviews.
Local meetups and events: Attending local game development meetups and events can be a great way to network with game app development companies and other game development professionals in your area. Some popular game development meetups include the IGDA (International Game Developers Association), Unity Meetup, and Unreal Engine Meetup.