Okay, I was in the borderline of accepting or rejecting this, but I think it's good enough to be accepted, though there is a lot to say.
The good thing of this hack is the simplicity. The design isn't a very articulate one, or gimmicky, but just plain traditional action, and sometimes it's good to take a break from those extremly articulate hacks.
Unfortunately, I spotted many errors, in terms of design, aesthetic, and technical ones. Sometimes you went way too flat with the design (look at infinite corridor, or the first two levels); there are silly palettes here and there (like the first fence you meet in the game); lots of sprite tile limits errors, highly suggested the insertion of a patch to fix this.
Other, relevant stuff here:
- "Infinite corridor"'s midway point doesn't work.
- the end of demo level, once entered, doesn't make you able to get out. You could start+select, but then Mario's OW position gets screwed.
2/5 for now. I recommend you to fix the issues and submit an update.