You know advent calendars? Those calendars that count down Christmas have chocolates for each down before Christmas. They're great. Season's Greedings is not.
Keep in mind, I'm speaking as an advent calendar. As a game, it's Angry Birds, and Angry Birds is one of the most enjoyable titles on the iOS. But as a advent calendar, it just doesn't work.
The reason for that is that Angry Birds is one of those iPhone titles that, sure, you might want to pick up and play, but it's also a game that you can plop down on the sofa with for the afternoon.
With Angry Birds, players get in a rhythm, and start going from level to level, collecting stars and smash pigs. But with Season's Greedings, it's difficult to get in that rhythm because each level is doled out bit by bit. It's tedious and annoying. The gameplay, however, is not.