Just finished playing through!

What I noticed is that you tended to use lots of gimmicks into a single level, often literally just once (like the screen scrolling pipe section to get a POW), which kind of gives the impression you put them there for the heck of it instead of making a level based around one and developing it. This also sort of happens with custom sprites like the yellow flying koopa since they're almost never placed in a threatening way, and those bomb-throwing moles were seen like twice in the entire demo. Despite this, the gimmicks were generally pretty well used, like the propeller block part (i fucking love that sprite) in the second level. The ghost house was the only one who didn't do this, based almost exclusively around keys and POWs and I found it overall pretty enjoyable. I also found the very first part of the the first level (when you hit the invis note blocks) to be pretty fun too!

Levels themselves were pretty good too, although first one is a little too empty, since it's mostly about those outline coins and maybe moles. The grassland levels could also use some prettier decoration, though I really like the architecture of the second level with all those ceiling slopes and stuff.

-Was there a way to even hit those turn blocks in the cave section with the moles?
-How should one get the secret exit in the second level when you're required to activate the yellow switch palace, which is only accessible when you find the secret exit?
-In the ghost house level, the mini sublevel with the POW and the key has a glitched custom sprite that falls right next to the door at the end. wuzzat??
-You could make the entrance to level 2 a "right pipe" entrance so Mario is automatically spawned facing left.

I think that's all. Good luck.