- Cart Life http://www.spelunkyworld.com/original.html (perhaps not as commercially successful as the others...but won a huge indie game prize, and is a great work overall)
One of the interesting things about games is that to the end user/player the majority of the value is the art and level design, two things which are extremely easy to divorce from the source (and thus license-able under whatever) so unless you're EPIC or somebody trying to specifically license tech open sourcing a game really doesn't make a lot of difference in the business model.
that said I'll add to the list DROD (one of the best puzzle series ever):
The engine of the mmorpg Ryzom was released as open source:
"Ryzom Core is the open-source project related to Ryzom Game. Written in C++, Ryzom Core contains the whole code (client, server, tools) used to make the commercial MMORPG Ryzom. Ryzom Core is a toolkit for the development of massively multiplayer online universes. It provides the base technologies and a set of development methodologies for the development of both client and server code."
How awesome is it that you can pickup an old game, one of your favorites maybe, read the actual source code - which might even have a modern analysis discussed at length by Fabien Sanglard - and then play the game... with all of the community's latest tweaks/optimizations... AND then ... when you come across a bug ... you can code the fix yourself!
After reading this article, I compiled Duke Nukem 3D and played enough to find something that bothered me. Just pushed a fix for horizontal mouse-look/strafing (to Fabien's 'chocolate' repo):
Something the author glosses over is that the Quake 3 engine is remarkably clean in its separation of the game logic from the engine--the use of "traps" gives something that very much reminds me of an operating system in some ways.
- A Dark Room http://blog.doublespeakgames.com/news/a-dark-room-goes-open-...
- Spelunky http://www.spelunkyworld.com/original.html
- MechCommander 2 (shared source, via Microsoft) http://www.neowin.net/news/microsoft-mechcommander-2-shared-...
- Asteroids (and many other Atari games) http://www.atarimuseum.com/videogames/consoles/7800/games/
- Cart Life http://www.spelunkyworld.com/original.html (perhaps not as commercially successful as the others...but won a huge indie game prize, and is a great work overall)