I took a look at this hack in Lunar Magic and boy it was glitched up (though it may be Lunar Magic acting up so I do not know). The level design from my perspective seemed fine though bland in certain areas and levels. I cannot really judge anything else. Here is part of level 105 which I am assuming it is a SMB1-like level:
I have no idea what caused the glitched graphics here (corrupted ROM?) so I cannot really judge the graphics and whether they seem fine. Moving on, here is the overworld:
I have moved the sprites and blacked out the unedited bits to take a better look. The overworld seems squarish and it could be better designed which includes varying the terrain, making the islands less square and making the paths less straight. Eventing works though the levels are visible (which is not a problem but it is unusual) and there are no actual layer 2 paths which will make the overworld look better. Also at the icebergs and the bottom of the islands you have minor cutoff as shown here:
Here is another one with eventing:
There are many more examples but I cannot point them out here. Quite a bit of work needs to be done before the hack is ready for submission.