Hi guys, I'm the creator of that game. I'm sorry that some of you had bad luck with the alpha version I have uploaded what i would consider a "beta". The code has been posted to codeplex as well so anyone that has a desire to "Fix" anything they hate is welcome to. A few notes:
1) I re-wrote the gameplay manager yesterday if you had any team-switching related problems try the new build
2) It used to do per-pixel collision [and just push you up if you were intersecting pixels, I don't really want to get into advanced physics here but it was a performance based decision] It now stores an array of hights and just makes sure your above it - this really improves performance but prevents deformation of the terrain
3) Its not perfect, if someone finds a large bug and wants to fix it/wants me to fix it post a bug and ill work on it...
If you like it, please digg it
http://digg.com/gaming_news/Zune_Game/
Codeplex project (source)
http://www.codeplex.com/Name/