About jigsaw ?

The website uses Flash, if you solve the puzzle it gives you a code or a link which gives you access to the giveaway.

But if you used HTML to solve it, it won't get you the code.

Make sure you're on the flash version and not the HTML5 to get the popup when you've completed it that has the giveaway link. You'll then have to put the code into the http://www.steamgifts.com/giveaway/[code]/ URL, and make sure you have the ending / or else it won't take you to the giveaway.

When you have solved the jigsaw, a green box ( I believe) will pop up.
Those letters in it, need to be used here in a GA link.
See