Don't read this if you have a tiny

[Ragnarök]

Not really. Here's the general rule: Since you're paid for the sprites you don't get even the slightest ownership of the game. You sold your work, thus it isn't exactly 100% yours. Imagine it like a physical piece of artwork: Once you sell it, it isn't yours.
On the other hand, if you give the sprites for free and want a portion of the profits, then you have some portion of ownership.

At least, that's from what I understand. Am I right, BAB?