Turned out that for some reason with hopper, the settings were automatically set to mouse controls instead of keyboard. I had to change it in the settings, which is strange because I don't use mouse controls ever. Thanks for your help!

I just bought Hopper on sale, but I can't turn the hull or turret. How does it work? Is there a link to the controls somewhere?

This hull is complete b.s. If you want to have a hull like this in the game, you also need to have it only for special battles and leave regular battles to the rest of us oldtimers. This is a joke.