Are the free iPod games on iTunes only compatible with iPod Touch?

There are free games that are on it iTunes and I was wondering if they only work on the iPod Touch and the iPhone. I have the new Nano, so I was wondering if the games would work on that too???
By free games I mean FREE APPS!!!

Where can I download free games that are compatible with Macs?

I want to download free game trials, but they are ALL only compatible with Windows and I have a Mac.
What are some websites I coud use that have the same games but are compatible with Macs?
So far I have only tried Pogo and Yahoo! Games.