For those who, like you, love to play games on their iPad, it is always recommended to purchase a device with a very fast processor because all graphic activities, especially games, use the device's resources in a stressful way. Obviously your current iPad Air 1st generation (firstly released in 2013) cannot meet these requirements.
The latest models iPad Pro 11 "3rd generation and iPad Pro 12.9" 5th generation, with Apple M1 chip, are certainly the most suitable. If you prefer a smaller screen size, you can take a look at the latest in the iPad Mini 6th generation series instead.
I suggest you use this page to compare the various models and make the best choice:--> https://www.apple.com/ipad/compare/?modelList=ipad-pro-11-3rd-gen,ipad-mini-6th-gen
Regards
Giulio