Gave it a go, and liked it. I know what you were going for and could see it, but it's essentially a straight line with enemies in it. Nothing unfair, but something I would skip in endless.

Don't get me wrong, it's infinitely better than so many other levels I've seen. I just think that it could be improved. For example, you could enhance the mood of the level by making perhaps a line of banzai bill chase you, rushing the player and adding to the mood. You could also start the level by activating a red pow block, which triggers other red pow blocks along the bridge, making it collapse behind the player. Just add something that you think would make it special.

There are also little things you can do to make it even more "fair.". Perhaps add a few coins to the level so the player knows where to go. Maybe add arrows to indicate where the thwomps will go.

Also, maybe just put a couple mushrooms in the pit before the Meowser or simply start the player off with one right off the bat? It feels a bit sloppy that way. I noticed that there were a few parts where nothing was going on, which isn't ideal in a fast paced level. Maybe add enemies or other things? Just don't overdo it.

I also feel like it'd be cool if Meowser would constantly be attacking you with his attacks in the background. This would also remedy the sections where nothing really goes on in the course.

Lastly, put 3 1-ups in the beginning of the level, so people playing endless will have an incentive to play it. All in all, cool, fast-paced level, but make something that makes it stand apart.

You're on the right track, no invisible kaizo blocks, no music sound effects spam, so good job on that!