Fun, non-linear levels of a decent length and consistent difficulty - all done with what SMW already offers. It's been a long time since I've seen a hack use layer 2 skewers, on/off line guides, P-Switch puzzles, even just creatively arranged sublevels. This demo almost has a nostalgic feel to it and definitely shows how much can be accomplished with a vanilla hack.
One thing that I found odd in the first few levels is the lack of consistency - you have multiple parts that use different sets of enemies and even different tilesets, which feels odd. The overworld can also use some work, as the current one is rather blocky and has some perspective errors, especially around the Toad Town island