I think that could be a modified version of VillageWorks, actually.

Think about it... a simplified roof, and the buildings would be easy (just make them single-story, or non-modular 2-story). Ground tiles are a snap anyway...

Some simple props, and there you go!

A different, cartoony feel for the textures would be okay, but not really neccessary. Just depends on how much work you want to put into it. Actually, I think it might be kind of counter-productive to purposefully make the textures simplified. I think the reason most "kid's stuff" is simple right now is because not much care goes into the design in the first place. Just because they're young is no reason to give them sub-standard textures.

I like the idea! Get 'em young!