Yes, simply. It would be a side-scroller. Advantages?
* Dynamic fluid physics for water
* Travel horizontally in either direction a virtually unlimited distance
* Travel vertically in either direction a virtually unlimited distance, but with perks: as you go higher from sea-level, the atmosphere thins and becomes darker until you actually reach space and see stars. As you go lower from sea-level, you will pass through actual layers of the Earth (similar to http://en.wikipedia.org/wiki/File:Earth ... nglish.svg, but more detailed than this -- i.e. at a certain depth it is known that there are these chambers and cave systems that are completely filled with water, hence the wells) until you eventually reach the core (if you have the tools)
* Less resource intensive
* Fun, small, side alternative (not as a replacement for 3D Minecraft though)