How do I change my gamercard background?

[KAZ01]

Not much to add. I want to put something instead of Sonic Adventure as the background.

 

[GamingKen]

Backgrounds are automatic, based off your played games. As far as I'm aware, there is no method to set a particular background.

 

[x3sphere]

Correct. For some older games we don't have backgrounds uploaded yet, though they can be submitted via the game page. That's why it's showing Sonic right now rather than Catherine.

I plan on adding an option to upload entirely custom backgrounds in the future.