Let me tell you something. This is one of the best 8-bit creations in SMW Central! As far as your level was built, you did quite an astonishing job with the ASM and EXGFX in the entire level.
When playing through the 1-level hack, I discovered the first thing that the title screen has "Desert Mario" and then the big word font of "8-Bit Mario World". My suggestion is to remove the small "Mario" text and make the word "Desert" bigger to fit with "8-Bit Mario World".
The music felt more like I'm playing the original Super Mario Bros on the NES. The music in the overworld, the cave and the castle fit perfectly well. The only major concern though is the underwater SMW music after sliding down the flagpole to complete the hack.
Besides a couple shenanigans for the hack, mushroom coins were fun to find in the hack itself. Although this may be a one-level 8-bit hack, I find this hack rather interesting for those who want to bring back nostalgia.
They are all one-level if not mistaken.
I'm really interested, do others based on various games, for example one based on smb2j, others based on various smb1, smb2 and smb3 hack,another based on various 8-bit NES,DOS and another old games, you may draw on various smb1 hack, on romhacking.net lots of hack where you may get ideas