Here are 2 cameos that you can spot with a careful eye in the Steven Universe show on Cartoon Network. The animators here clearly know (and want to add) video game references. 

The above left cameo has what's probably supposed to be Cloud Strife from Final Fantasy 7, possibly a Roblox looking guy? and an all-blue figure that's clearly supposed to be Sonic, even if it is just an outline of a spiky guy with pointy shoes and gloves. These seem to be sitting on a shelf. The right side cameo has a Pikachu-moogle looking thing, a guitar costume rocker that looks like maybe Adventure Time-esque & then...........Sanic. The poorly-drawn 'gotta go fast' circle Sonic 'creature' from a crayon scribble that got the name "Sanic" as a meme. Because it's just a meme...those aren't copyrighted at all, so it can be directly drawn and then still count as a cameo. It's good silly fun!