So, today, as WR is feeling under the weather, I will be taking his spot as a game reviewer. What I have for you is a flash game, but has the feeling/gameplay of a downloadable. Continuity Game http://continuitygame.com/ (sorry, I don't get how to post pictures/integrate links, so we will have to go old style). It is nominated for the IGF award (in the top 10), and is definitely my favorite out of the rest.
It starts out as a normal platformer, aka, you jump from a platform, grab a key, and then jump to the exit. However, there is much more depth than that. The game area is made up different "platform pieces", and when you are zoomed out (The player pauses during this), you can shift pieces around and about, (like the physical game where you push pieces over/up/down to make a picture, and there is one square missing) to rearrange the actual level that the platform character uses. A genius game, in my opinion.
Screenshots: