Can I register a retail boxed copy of a game with Steam?
Long story short, I purchased Uplink through Introversion's website, and not through Steam. Turns out that was a mistake, as I paid 3x the cost going through the developer's website, but I digress.
Uplink is available on Steam, but I don't want to have to purchase it again. I know that I can add a non-Steam game to my library. So, my question is this:
Is there any way to get the Steam version without having to buy the game again?
I ask, because I'm worried that if I switch computers, I'll lose the copy that I already I've already purchased outside of Steam.