XNAMatrix has published a list of entries to the "Warm-Up" phase, which so far amount to 20 games in two categories: 16 of them are 2D, and the remaining ... well, let me see ... hum, I think is ... 4! Yes 4; ... ahum! ... well, the remaining 4 are 3D ... (sorry for the delay but I had to open 'calc.exe').
The page provides links to creator's pages, download sections as well as screenshots.
If you want to submit a link to your entry just contact them.