Trackballs

Trackballs is a marble game in three-dimensional space, inspired by “Marble Madness”. It is released under the GPL, and was developed by Mathias Broxvall until a long hiatus from 2007 to 2017 after which a new maintainer picked up the project. The latest version before the hiatus is 1.1.4, released on 2007-05-25; now version 1.3.1 is available. It is written in the C++ and Scheme programming language using the SDL library. Support for OpenGL standard 3.3 is required.

In the game, the player controls a marble (not the field itself) over a 3D labyrinth, avoiding moving spikes, deadly force fields, enemy balls, and marble-shattering falls, all while seeking the goal at the end of the level.