Upside-down half Ground tiles.

So, we've got tiles for the bottom halves of Ground tiles. but not the top halves. How 'bout we add some o' them there tiles to this 'ere collection? *shot*
A potential issue I can see, though, is how all the other currently-existing Ground tiles could possibly morph with any new additions, and yet not morph any differently than they do now (wouldn't it break currently-existing levels to add these, maybe?).
A potential issue I can see, though, is how all the other currently-existing Ground tiles could possibly morph with any new additions, and yet not morph any differently than they do now (wouldn't it break currently-existing levels to add these, maybe?).