I agree. The engagement and stickiness of the game itself is key to long term success. I am hoping that Land and Tower Defence provide some interesting new gameplay opportunities.
I still like to play from time to time. Mainly to try out new strategies or see if I can do better than my Archmage bot. If I am 100% focussed and not over-tired (rare with 5 kids) then I can do better.
But it is much harder to win than it used to be and personally I don't like losing. :-)
Thanks for your comments. I am excited for TD though that does nothing to enhance the core game. I'm ambivalent about land in many respects, particularly when it comes to your average player who doesn't own any.