Wow, this is just superb!

Pixelling-wise, the technique is ace; tile-wise, I guess not much more can be accomplished with a single tile

The only thing that does not convince me is the top of the trees: the leaves themselves are beautiful, but the way they fade to dark rather gives an impression of flatness and over-stretching... edit: another factor that contributes to this impression is that leaves perspective changes too little.
Dunno, maybe it's just me being unable to read it

Can't explain it any better, sorry

saimo