iPad Mini 1 won't load graphically-intensive IOS 9 games

My iPad Mini 1, running IOS 9.3.5, won't run some graphically-intensive IOS 9 games I've downloaded from the App Store.

when I try to run Revolution, Infinite Shooting or Breakneck, I either get to clicking 'Start' in the game and then IOS returns me to the home screen, or I get to returned to the home screen just after clicking the icon.

I've only used half the storage in my iPad and I've tried hard resetting the iPad, resetting network settings and changing Wi-Fi network but nothing works.

Another game I've got (Swordigo) is also graphically-intensive but runs every time.

Does anyone know what the problem might be?

Thanks

Paul