The buzzing engine sound of the rockets is in fact the authors' Startup-sequence used as a sample(!). Also, the sound when the two ships collide is the sound of a radiator being hit with an extension cord, and the sound of a ship being submerged is taken from an orange dropped in a coffee pot.
In 2008, the source code for GF2
was released. It consists of roughly 11 000 lines of "sparsely commented assembly language".