In the time between my last post and now, I've grown pretty fond of the idea. I think these are the best LEGO games so far, since it's extremely easy to make your own game. The other games all have separate rules, so in order to make a new game, you'd have to come up with your own rule set. With Heroica, you can use the universal (I presume) rules, and change up the mission. All you have to do is make a new map, add some new objectives, and you're golden.
That being said, I plan on making a few of my own missions, and I have a bunch of dark tan 1-stud tiles waiting to be used for a desert scenario.