I'm sure this is not the first "New Super Mario World" I've come across.
Anyways, I've just finished playing the demo. You really managed to make this few like a new SMW. It feels like an improved version of the game, with better palettes (great job on them too!), a remixed soundtrack, a few new graphics and enemies and a slightly different playability. Everything's looking pretty polished (aside from the layer 1 garbage on the top right of the map
). The level design felt to me pretty faithful to classic SMW's. This is definitely going to become a great hack if you keep developing it this nicely. :>
Just for the sake of making something up to complain about... Those blocks in that "outer room" in the castle level really don't look good... I believe I've seen them before in some of those SMW's beta screens? I really could be wrong on that; still, I don't think they really fit that well with everything else. Maybe some shading would make them look a bit less too simple.