The show is Steven Universe, a relatively new animated series on Cartoon Network about a young boy called Steven, and his intergalactic female warrior friends. Its 16th episode, 'Steven the Sword Fighter' was aired recently and surprisingly, it was full of video game references!
In this episode, Steven is about to learn the art of sword fighting... with video game figurines.
Here's a Moogle from Final Fantasy, with Pikachu's body:
Sonic... I mean Sanic!:
It didn't end well for him though:
One particular fan with lynx eyes even noticed something else in the same episode: An awesome sword-fighting homage to a classic anime, Revolutionary Girl Utena (see the comparison GIFs below). That and Gitaroo Man added, I have to say the creators of this show have extraordinary taste!