As Hagatagar implied, you just did by registering. Links are only masked for unregistered visitors, and fully visible to registered members.
Then you just have to goes on the game thread of your choice, click on the link of your choice, depending on your OS. There's more than on link by game and platform (Windows, Linux, etc.), but all lead to the same game; it's just redundancy to ensure that the game will be available over time, and to let people pass over some download restriction with one or another hosting site.
You can also use the search feature in top of the page. When you're on a game thread search for "compressed" and, if a compressed version exist for that game (and that version), the post will be among the result you'll get. Compressed versions are identical to the original game, but with lower quality for the images, what lead to a smaller size for the archive; ideal if your ISP have quota or if you've a low download bandwidth. Generally compressed version don't really looks worse than the original one, so don't hesitate.