Playing Super Monkey Ball with a monkey in a ball just makes sense

Gamers could get an edge in Sega’s Super Monkey Ball with the help of a unique DIY controller: a literal monkey in a ball that can be physically rolled around instead of mashing a joystick on a gamepad.

Super Monkey Ball requires players to tilt and roll a series of complex floating platforms to control the monkey’s movements, so Sega designed the original arcade versions of the game with an oversize trackball controller.

That wasn’t carried over to the console versions of the game, and since arcade machines typically cost thousands of dollars, developer Tom Tilley decided to design and build a much cheaper solution made from recycled and 3D-printed materials. “I am a software developer, but I worked for about eight years as a fax and cellular phone technician in the late 80’s, so I have some small amount of electronics knowledge that comes in handy with this sort of thing,” Tilley told The Verge.

Tilley, now a software developer in Australia, spent almost 10 years lecturing at a university while living in Thailand, where they also ran a class that challenged students to come up with unique alternatives to game controllers.

It was there that the idea for a giant trackball made from random recycled parts, an optical mouse, and a basketball, came to fruition. A base made from cardboard holds the basketball in place and allows it to freely roll in all directions with the help of three salvaged roll-on deodorant containers that serve as plastic bearings. Beneath the ball sits an inverted optical mouse upgraded with another deodorant bearing that rolls whenever the ball does, making it easier for the mouse’s sensor to detect its movements.

The original version of the trackball was built to play a 1986 Japanese arcade game called Armadillo Racing, but it has since been modified by Tilley to play other games, including Katamari Damacy, with a soccer ball. Using it to play the Nintendo GameCube version of Super Monkey Ball through emulation required an additional modification, Tilley told The Verge.

A 3D-printed recreation of the game’s main character, a monkey named AiAi, rides inside a transparent plastic sphere on a weighted wheeled base that keeps him upright at all times. It’s a charming upgrade, but the clear plastic created a new problem. The sphere’s smooth finish didn’t offer enough friction to move the deodorant roller on the mouse. To fix that, Tilley had to swap that part out for a small rubber ball rolling on metal bearings so the mouse’s optical sensor could detect AiAi’s movements.

To make the GameCube version of Super Monkey Ball work with a DIY trackball, Tilley uses a scripting tool called FreePIE (Programmable Input Emulator) that inverts the signals coming from the mouse and maps them to a virtual joystick that’s compatible with the emulator software.

The first new game in the Super Monkey Ball series in a decade releases on the Nintendo Switch this week. If Tilley can make the DIY trackball work with Super Monkey Ball Banana Rumble, he just might dominate the game’s multiplayer mode.