Well it seems that you've got the basics of level design down well, so congratulations on that. But although your thok barrier and fof's and rings are all in order, you've got a couple of things working against you:
-You're starting off attempting to make your level difficult. This isn't necessarily a bad thing, but I would generally tell new level designers to stay away from trying to make difficult levels. Challenge and difficulty is something hard to do correctly, even for experienced level designers. For beginning level designers, attempts at hard difficulty usually come off as cheap or lackluster, and your level suffers kinda happens to be both.
-Your theme is lame. Now, I know that difficult platforming on LSD-colored platforms in space can feel pretty epic, but again, it's something hard to do right. Even Prismatic Angel Zone, which pretty much invented this genre of level (I think), was a pretty bad zone, even IF you felt like you were doing something important. It also gives you an excuse to place a bunch of bland square platforms in a big empty room because that's just how the theme is. It's a pretty lame way to go about designing a level... which brings me to my final point.
-You really need to improve your overall level architecture. This is what usually sets apart the decent levels from the obvious "noob levels". Doing this right takes a lot of intuition, and I can't really explain how to do this properly aside from giving you this singular piece of advice: Study the good levels. They can be the official levels or from a level pack, it doesn't matter, as long as those levels just feel good. Study what makes them fun, what works and what doesn't work, and compare that against your own level. Then, try to implement the things you like. I'm not saying to straight-up-copy, just assimilate the good aspects of those levels into your own design. Maybe you'll make something great!
Aside from that, you've done a decent job. I've certainly seen worse levels before. I actually really liked that part where the ceiling almost crushes you, and I feel like I had ample time to avoid it while still feeling like I'm in peril. Kudos for that.