Just when you thought one of the world's greatest ever video games couldn't get more perfect, along comes modder Skelux to pile more icing on top of the cake.

Super Mario 64, for 16 years a singleplayer adventure (well, DS version excepted), has been modified to include a co-op mode. You can see it in action above. It looks like a blast.

What's really cool about it is that the two can interact, adding in effect new co-op moves to Mario's arsenal.

If you want to try it out, though, you should know that you'll need to play it on a PC via an emulator, which for some people crosses a line they don't enjoy crossing.

You can get both the co-op mode, and a Mario 64 "expansion pack", at the link below.

Super Mario Star Road [Site]