Terry releases source = piracy is really really easy = Terry:
Pirates:
Fanbase:
.
It's fairly easy to rip/redo the graphics and SFX and make a clone though.
Piracy is already really easy, with the game having no DRM.
Pirating the game is currently far easier than downloading the source code, compiling it, and pirating the assets (sound, graphics, level data, script, etc.)
And what's so terrible about people making VVVVVV clones? Companies like Zynga that steal games like a living could easily whip up their own version of the game because they're large companies with lots of developers, and they wouldn't have any legal liability whatsoever. On the other hand, if they
did decide to steal VVVVVV's source code, they
would get in legal trouble for it. "Open source" means "anyone can look at the source," not "anyone can do anything they want with the source."