OMFG! Dude, now that I see it, you really master game designing, doing sketches and basic the sprites off of them is the correct way of doing it! I mean wow, that palm tree is just wow! (eventhough it's not finished, as I can see the brown part lacks some shading).
For other fellow developers, this is the way to go, just look at Ark 22 made by Srehpog, it has tons of pages dedicated to concept art and tiling, which were then used in the actual game, the background part of the game is essential.
Anyhow, having these qualities, I must await a pixel perfect, non-glitched, and just a plain Nintendo-like quality (if not better, seeing how I loathed LTTP's walking engine >_>), from you
Just keep up the good work, I really hope to see this game at the next z3!