I always liked the first Wii Play game, but I must say this one was definitely an improvement upon the first.
This one is more inviting for multiple players – especially those that are new to the Wii itself. Rather than placing emphasis on learning the buttons and the motions together, the game opts more for learning the motions first. Twist the remote, learn how sensitive it is.
I think the favourite group game would have to be the skipping stones. That one really displays how careful you have to be with the tilt and really gets a good feel of how hard to swing for certain motions and such.
The only disappointment I have with the game is that there aren't enough four-player games. While the two player games are EXTREMELY fun (especially the umbrella racing!), it would have been nicer if the majority of games were four player.
Then again, that's what sharing and taking turns is for. :)