The second set has ten games, compared to the eight games of the original set. One of them was a mystery Kickstarter exclusive so that was a fun surprise. Backers have been asked not to spoil that game so all I will say is that it is the game that probably has interested my wife the most out of the new set.
While it's going to take us a while to work our way through the second set, I would say that Chris Handy has upped his game with these games. On their in-house game of complexity, only one of these games is listed as casual. And that game, DIG, looks like it would've been considered intermediate in the original set.
This isn't necessarily a good thing. I personally thought that TAJ from the original set, rated challenging, ended up being fiddly due to the relative complexity of the rules for the length of play. Oh, I thought that it was innovative and ambitious but it was near the bottom of my enjoyment level.
In general, I would say that the second set really looks like it's aimed more of a gamer audience. The first has a wealth of games that are really good for a casual play and for non-gamers. It will really be interesting exploring this new set, which I truly believe was designed with a different set of goals.
I also want to note that this set has more two-player only games. Which is great by me, since a lot of my face-to-face gaming is with my wife after the toddler has gone to bed.
While I had high hopes for the original set, it exceeded my expectations. Heck, while it is not my favorite game from the series, I think SHH could break out with the mainstream audience. So the bar is set pretty high for the second set. But my hopes are still high. It's not like lightning struck once with the first set. It has five different games I know I will be playing for years to come. That's a really promising batting average.