From reading the reviews left on iTunes most people are quite happy with them, but worth the five dollars you are asked to spend? I don't quite agree with that. You can also use Rockbox and Linux to play just about all of those games or variations of them, plus a few more options.
I have Cubis and Bejewelled - the games are excelent!!! I found myself playing all the time. The only thing the games eat battery too fast. It's very easy to play and the clickwheel works beautifully, you can listen to the music while playing the game.
Yes, the original games are still on all the iPods, [bold]only the 5G iPod Video[/bold] supports the movie downloads.