FreeGameDev

The source was apparently release quite a while although I just noticed it now: https://github.com/farbrausch/fr_public
License: 2-clause BSD
Language: CPP/Small amounts of ASM I think
No idea what OS it compiles on, maybe just Windows.
Was pretty impressed by it myself back when it was released.
If you haven't Heard of it Before, check out Wikipedia's article here: http://en.wikipedia.org/wiki/.kkrieger

Hi

I just show you an image for those who don't know this game (source: Wikipedia):

That looks very nice - no idea if it plays nice too though. :P

97,280 bytes! Its graphics is wonderful, especially considering the size of the executable.

It's old and it's only a tech-demo with very little real world game application.

Back then it was quite amazing though.

Yeah farbrausch was an Amiga demo group, before moving on PC. Their speciality was compression and gfx.

Awww our greeny years