Chris Stauffer at myITForum.com

****BETA**** Games for Zune

 Finally Games for the Zune.

 Guides to install Games

http://www.zuneboards.com/forums/tutorials/23605-installing-game-xna-your-zune.html#post216424
 
http://www.zunescene.mobi/forums/index.php?topic=37524.0
 
http://www.zunescene.mobi/forums/index.php?topic=37503.0

 
Here is what I uploaded so far. As I find more I will add them to this blog post:

 
These guys are going crazy:

http://forums.xna.com/thread/60532.aspx

The first Zune Clock (Not a Game)

http://www.zuneboards.com/forums/download-completed-games/23700-ctp-offical-zuneboards-clock.html

GAMES:

Alien Aggressors
http://nick.gravelyn.com/2008/05/07/alien-aggressors-zune-edition/
(For the updated ZunePad version files, go here

Galactic Wars 3 (Zune - Source)

http://focusedgames.com/Content.aspx?id=175

Rock Rain:
http://www.sharpgames.net/Noticias/Rock+Rain+Zune.xna

XNA Tetris:
www.csc.calpoly.edu/~mwazny/tetris.zip

Collapse:
http://www.guyer.us/downloads/collapse.zip

A Bejeweled Stlye game:
http://focusedgames.com/downloads/MatchEm_050908.zip

 Fonts (Grab these  fast because every site that had them mysteriously disappeared)

http://www.4shared.com/file/46099068/9ef9bbfa/Segoe.html

http://go.microsoft.com/fwlink/?LinkId=104778&clcid=0x409

Also note that exiting most of the games causes the Zune to reboot including the Clock. 

Updated:

Major list of games: 

http://www.zuneboards.com/forums/download-completed-games-174/