The starring enemies in this course are unchained Chain Chomps. I discovered something interesting about them. Once they emerge into a course, their motions are not generally affected by Mario's position -- unless he collides with one that is, enemies will change direction in order to bite you. But mostly they just happily bounce along not caring about you at all! They will bounce off of other Chomps though.
This level sends them through predetermined pathways dictated by blocks in their way. They don't go through any seriously convoluted routes, but they keep respawning from pipes. It's best to leap over them as they overtake you, then continue on.
One thing I'm particularly proud of here is the wide array of ways you can tackle this course. There are progressive powerups that help you along the primary route. There is a secret sky route you can use if you happen to find a Weird Mushroom (there's one in a hidden block at the start), that has lots of long, long jumps, some of which can only be made with Weird Mushroom assistance, but of course if you fall out you still might be able to land somewhere in the normal course and finish it that way. There's both a Star and a Shoe Goomba (shoes can stomp Chomps) in hidden blocks shortly after the main checkpoint, and there's a P-Switch that makes the last part easier if you're fast enough. There's also a pipe midway through that leads through a short underground section that poses its own challenge, but if you take it you'll have to bypass both the Star and the P-Switch.
I don't have a very good handle on how difficult most people will find this course. I think it's relatively easy, but I made it a bit easier right before uploading to remove some one-block landing spots right at the start that I find no problem, but I've come to realize might be troublesome for ordinary players. Chomps are intended to be the main problem here anyway. I predict it will end up with about a 8-9% clear rate.