'Super Mario Galaxy 2' split-screen co-op mod may hit this year

Two brothers are working on a Super Mario Galaxy 2 mod that will bring true split-screen co-op support to the game, and for the pair of longtime modders, it's their most ambitious project yet.

The only multiplayer mode in Galaxy 2 lets a second person play as an orange Luma, a helper character who can attack enemies and collect items. But earlier this month, Robert Chadwick, the user MrBean35000vr on YouTube, posted a video (see below) of horizontal split-screen play that he and his younger brother, Alex, hacked into the game. It's an immediately impressive proof of concept, although it's apparent that there's still a lot of work to be done. Robert told Polygon in an email that while it's "difficult to predict" when the mod might be finished, he and Alex "hope to release a playable demo before the end of the year."

The Chadwick brothers are computer science students in the UK who began modding Wii games in 2008. "I had played far too much Mario Kart Wii and thought it'd be really nice if more tracks could be added to the game," said Robert. So he and Alex, who goes by the moniker Chadderz, examined the game's files, and eventually hacked the Rainbow Road track from Super Mario Kart on the SNES into Mario Kart Wii.

It was their first custom track, and as something no one had ever seen before, it remains their most popular video by far, with over 300,000 views since August 2009.

When asked why he and Alex have kept this up for years, Robert said, "We like seeing others using and enjoying our mods, as it makes all the effort put into making them seem extremely worthwhile."

In this brotherly collaboration, each member has his own areas of expertise. Alex is "the main mastermind behind the magic," said Robert, since he "does the majority of the modding and coding." Robert helps out, but he mainly serves as the idea man who takes care of "menial tasks," and also handles the team's video production duties. For him, the allure of modding is that it's a different way to enjoy a game he already loves. Alex, on the other hand, thrives on the coding challenge. According to the YouTube description for the Galaxy 2 video, he has been the mod's driving force so far:

Chadderz made some astonishing progress on this in the past couple of weeks, successfully splitting the screen, making each character react to a different controller, making the buttons work properly, making one Mario and one Luigi appear in the first place, and most importantly... making sure the game doesn't freeze.

The mod has come a long way since Robert and Alex first began work in January 2011. The duo worked on it for a month or so, but quickly put it aside after finding it "impossibly hard." They returned to hacking Mario Kart Wii, and with the knowledge they acquired from that work, eventually redoubled their efforts on the Galaxy 2 mod. In just two weeks, Alex turned a "malfunctioning mess" into the game in the video above.

Robert and Alex have a solid foundation — Luigi already comes with his characteristic low-traction physics — and they hope to deliver a fully functional mod. The plan is that Mario and Luigi will have individual health bars and camera control, while they will share lives, coins, and Star Bits; if either player dies, both are returned to the most recent checkpoint. Most importantly, the Mario Bros. can interact with each other; after all, no cooperative experience is complete without some capacity for friendly trolling.

In just two weeks, Alex turned a "malfunctioning mess" into a working mod

Once the mod is ready, the brothers will release it through Riivolution, software that allows Wii games to run "patches" from external media that alter and add elements such as textures, levels, characters, and music. Gamers will need only an SD card for the mod and a retail copy of Super Mario Galaxy 2.

For this modding team, Galaxy 2 may just be the beginning. "Perhaps if this project proves successful," said Robert, "we may attempt to bring split-screen multiplayer to other Wii games that do not feature it already, such as a Zelda game."