It was basically a cartoon version of the formula that Marvel Studios is now mining to great success, and which video games has seen most visibly in Nintendo's Super Smash Bros. games.
We've also had Mario + Rabbids, and the at-one-time-unthinkable pairing of Mario and Sonic in a bunch of official Olympics tie-ins, in addition to the likes of Capcom, Square and Disney, and Konami mashing up various franchises.
Here are ten more of the lesser-known gaming crossovers.