I did some experimenting with low resolution rendering of the game. Essentially I rendered the the scene to a texture and half or quarter resolution then scaled it back up to full size using nearest neighbour filtering.
The results look pretty cool. At the lower levels of resolution the graphics become somewhat abstracted, a representation of the object rather than an attempt at fully realising it. The greater the abstraction, the more that is left to the mind to fill in. Go really far with this and you end up in the realm of dwarf fortress.
Halving a resolution like this also has an added performance advantage. Half the amount of fragments are being pushed through shaders and textures can be of lower res.