I updated the game with D2D
 

I also had the steam version of the game. So when I try to start the game, it asks me for a activation key (Which I OBVIOUSLY don't have.) There's also an unlock request key and I try using it, but when it asks me to choose the website I bought the game from, Steam isn't there.

So what the hell? This is really pissing me off.

Hate to tell you, but if you haven't done so already you need to uninstall and reinstall your game using Steam ONLY. Steam's clients of games are not compatible with outside patches.

If you want a patch for a steam game, you need to either wait for steam to patch it, or find a sponsored steam-approved patch that is compatible.

Sorry if this is bad news, and I realize your post is almost 2 months old :(

Steam version should be already 1.1 and contain the water gun and other improvements.