Played with controller, which I know wasn't recommended, but I don't play HiT with KB+M so my review will be based on my playthrough with controller.

As I was playing, I felt like a lot of areas weren't that greatly designed. It was very linear and narrow, requiring a lot of jumps and then one long jump that I can either barely make or can land on just fine, with no idea how I caused me to make or just make the jump.

However, just because it's linear and narrow doesn't mean it's bad, I just felt it was an odd choice for a starting section where a player would most likely be learning how to the hat effects Hat/Bow Kid. I feel for this starting run area, it'd be best to put platforms under the gaps so if the player falls, they can easily get back up and try the jump again.

I have no idea if you could do this, but the ramp section after the big long jump would be great if you found a way to program in it flinging you across it as if your momentum actually flew you other, rather than you running straight off the edge of the ramp and going in a straight line.

After the cogs section, we get to a long ramp where you have to make a large leap that I couldn't seem to make consistently, and more often missed than made the jump. I thought I had to run from the very start of the cog before the ramp and run up it, which worked well the first time, but didn't work so consistently after replaying the level to make notes for my review.
I imagine this is because you're intended to run without stopping throughout the entire level, which would make sense as the level was designed for mouse and keyboard and the mouse would be able to make quick shifts left and right without taking your finger off the A button to make jumps.
I did stop at the very end to see if there was a grapple hook I could use as I thought the jump was way too big on the first try though, and after not seeing one, I just kind of jumped with faith that I'd land.

After that jump, I found the platforms too narrow to move the character without running off the edge, however I'll chalk that up to this not being designed for controller and this can easily be fixed by not holding the analogue stick all the way forward and, instead, easing your analogue stick around half way between the centre and edge to make sure you run fast enough to not feel slow but slow enough to have easy control.

Now we get to the umbrellas you bounce off of. These are great, as they have plenty of surface area to land on given how this is the firs time the concept is introduced in this level.
I do have one criticism though: When first playing, my natural thought was "Oh I want all the rings, I'll go collect all of them!" only to realise that, now that I could not regain my momentum, I could not make the gap to the first checkpoint and had to force a death, starting all the way from the beginning.
I guess my only suggestion is to not put so many rings there? Or make it where the rings are in the air as you bounce towards and away from the umbrellas? Overall though, I felt that section was good minus that one instance of me being silly.

I felt this section was pretty good. The narrow platforms are more suited here if we'd consider the previous section a tutorial to how the level and Sonic hat mod works. I may have fallen off one or more times, but after a second playthrough I felt it was more easier than I remember.

I also enjoy the sections where you land in the boxes and have to constantly turn. The sharp corners made it interesting to me, even if some people could consider it an interruption of flow. I would say it gives me more time to breath, it makes it feel more like a level to me.

I especially enjoy the part where I bounce on an umbrella and out of the top of a cube. The design of the cube made that section feel like a spectacle to me that enhanced my enjoyment of the level.

This section actually feels really good. The ramps don't give me that fling that makes me feel like it carries momentum, and it can be kind of hard to control with a controller given how the mod is so sensitive to turning, but that is no fault of your own.

I didn't get the use of random pillars at first, however, until I slowed down to collect all the rings and accidentally bump into one. I feel the fact the pillars are deadly could be better communicated.
I really did enjoy that there was more and more as you bounced from each section, and how you put rings between two close together pillars to challenge the player. It was a nice touch!
One suggestion I'd make is having a section where there's a broken pillar that's on the ground, but has a ton of rings over it with a open path next to it with no, or a small amount, of rings to make the player challenge themselves more!

Also, the transition through smashing the clocks is a great touch that I enjoyed throughout my time with the level.

I felt the tubes mechanic was pretty cool, though it did feel like just running from one section to the next without much action. It did make me think "can I run under these?" like it were a Sonic Lost World stage, but I didn't tempt fate and just ran on top of them.
I would also make the first tube bigger, with each one getting smaller as the sections go on.

It also was a little confusing on where to go from the umbrellas if you have depth of field on, so I would suggest adding a line of rings towards where you need to aim towards so you don't just blindly jump into the air like "...wait where's the next platform?"

The narrow platforms are not at all great on controller, causing me to fall down often (especially since I have to turn so quickly and the depth of field making it feel like the platforms 5 feet in front of me were blurred to all hell, making it hard to navigate). I disabled depth of field and I felt it was easier, but I did slow down to make sure I didn't fall off.

The giant blue mafia statues did make me me think they were going to be enemies I could fight, which I thought would have been funny if they came to life as I approached them and chased me. You don't have to add that in, it was just a thought that popped into my head.

I feel it was fine. Very short, not too hard, nice to speed through, and the umbrellas actually gave me time to adjust my camera to run across the narrow paths (along with rings pointing me in the right direction).
Overall, not much to comment on and not much to dislike either, was a well made section.

After seeing the giant birds who didn't attack me at the start of checkpoint 2, I thought "Oh man, are there going to be enemies in this level?! That'd really be nice to have them as obstacles!" and was disappointed when there were none.
So imagine my surprise and joy when I saw that there were enemies to fight! I felt it was a great change of pace to the level, even if I wish that there were more of them that acted more like obstacles to avoid that you can kill if you want, much like the birds who try to bonk you in the section before the umbrellas.

Speaking of the umbrella section, I didn't feel overly confident in my ability to make it to the next section and often ended up slowing myself down so I'd land on one rather than accidentally falling short or overshooting one. I feel a camera shift to angle downwards could help this way more, so I can see what umbrellas are directly under me while I'm falling.
Nothing too drastic! Just a simple pan out and slight tilt so I can see what's in front of and below me.

Also, I noticed there was a secret path above the boking birds that had a ton of rings on it, and I loved that. It was something easy to miss, but rewarded you for playing well and felt nice to breeze through the umbrella section after getting up there.
I wish there were more alternative paths like this, specifically paths that you end up taking if you miss jumps that are more challenging while the main path that's currently in the game is the "easier" one to reward you for being good at the level.
This'd help make it feel less linear and more rewarding for actually playing well, along with adding replay value and giving more areas to hide tokens (which would greatly encourage exploration)

It's ok. It doesn't feel like an ending though. I feel it would be great if this section felt more like it was all the elements of the previous checkpoints coming together to really test you!

Maybe make some of the platforms bigger and add a few bonking birds who'll try to bonk you off the platform if you don't get past them fast enough, with another platform containing those deadly pillars from earlier, and a series of umbrellas to bounce off of to get to the clock you have to break into. Then the final part to get the time piece could be a small gauntlet that reveals the time piece, like how killing all the birds would reveal the umbrella to get to the next platforming section.

A lot could be done here to really wrap this section into a nice package. However, I do really appreciate the platform that gives you a view of the whole level, it made me appreciate the journey I took along the way (even if I did have to disable the depth of field effect)
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2216010191

I wanted to be fair to this mod creator and tried it in the way it was intended to be played to see if I feel it's better when done so.

My thoughts haven't really changed, but it did feel a little better to turn corners I couldn't quite make on controller at full speed. Full disclosure: I don't normally play this game with mouse and keyboard, so I went to the hub area and quickly got a grasp of some of the controls that were essential to the stage.

Other critiques
The music doesn't loop properly, which does feel off. It makes me feel like I'm taking way longer than I was supposed to in the stage and that I was playing poorly for the music finishing before I was, but maybe I'm looking too into it.

Do I think this level is bad?
No. Absolutely not. I would say that I can see why some people would even consider it really good, but I just see it as a stage that has room for improvement to make it go from a good stage to a great stage.

Would I recommend it?
Yes, even if I personally didn't love it. It is fun at times, even if some jumps feel like pure luck. Overall, I'd give it a 6/10.

I hope this review wasn't too harsh. Given it was one of your first levels, especially a level of this genre that isn't common in the workshop, it was a great effort and I hope that there's an Act 3 that improves on the gameplay and concepts of this one! (Edit, I thought this was Act 2 for some reason. I'm off to play Act 2 now!)

I'll be sure to check out some of your other level mods. But until then, that ends my review. :)