Polar Opposites?

After finally going through the game trade publications I picked up at GDC Eu / Gamescom, a few new ideas started floating around in my head.

The one I am currently pondering most about is the possibility of mashing up the sandbox and point and click adventure genres.

In the former the player is given a universe and some tools to play with. Testing the boundaries, coming up with creative ideas and generally letting the players find their own way to have fun is what it's all about.

The latter has a very rigid and linear construction, and when the rules aren't followed, the player will find himself stuck.

I'm currently favoring an episodic approach to a possible genre bender: On one level the player will have a world to play with, but will unlock certain pixel hunting, inventory combining at designated points. 

One example might be a part of a pantheon of gods: Part of the game would involve building, populating and molding a world of your own, but to gain further skills you must perform fetch quests for the other gods working with you.