Well, I loved Seasons too. The Halloween theme was very cool, but the difficulty seemed to ramp up a lot more so than the original game, almost to the point where it felt like a completely new game. Which, I guess when you think about it, it was a brand new game. After the Halloween levels were complete, I wasn't sure what to expect after that, but once again, I was shocked.
The next set of levels were Christmas themed levels. They were all fantastic, with new physics based around snow, presents and other items. It was the same blueprint, sure, but again, it felt like a new game.
Since then, they have continued to push out holiday or season based levels, now into year three of the cycle. Each time they update it, it seems to be better than the last. They have used Seasons to introduce new types of items to smash, new birds, new physics and new ways to play Angry Birds, when it comes down to it.
I still love playing this game, just jumping around from season to season, holiday to holiday, year to year, trying to find all the improvements and upgrades they made. I still find the levels, especially when going for three stars, harder than the original game, but that's one of the most compelling aspects of the game.
But just when I thought the Angry Birds franchise knew all the ways to reinvent the wheel with Seasons, they changed up the game once again...