Blendo Games built Quadrilateral Cowboy, its retro-style hacking games released late last month, using id Software's idTech 4 engine, the same tech that powered Doom 3. John Carmack made it a habit to release a game's source code down the lines in order to give the community more tools to develop their own creations, and Blendo is following in his footsteps by releasing its source code to the public.
"The source code is written in C++ and includes the solution files for Microsoft Visual C++ 2010," the developers note in the FAQ. "The source code is released under the GPL license."
Considering that Quadrilateral Cowboy relies on retro-style aesthetics and technology—you do your hacking on a computer outfitted with 256k of RAM and a 56.6k modem—it's appropriate that the game's source code weighs in at a compact 12 megabytes.
Anyone who has been following the game's progress for the last few years probably saw this coming. Back in 2013, developer Brendon Chung tweeted that "Quadrilateral Cowboy source code will be released with the game. Sooooo if you want to add Oculus Rift support that'd be rad."