I finished the level with 10/13 trinkets.
I'll try to express my opinion, but I'm not a game reviewer.
Originality: Some trinkets were original. Rating: 7/10 
Level structure: I like levels with sub-levels (which you can do at any order) and with secrets. I also like open areas where you can explore Rating: 8/10 
Story: So, they got there through a big warp token. How can Vermillion be a wizard while exploring dimensions, considering the existence of teleporters, etc.? Also, there are 2 Vermillions and no Vitellarys. I liked how an area is a city (Bel-Air), and the fact that Violet wanted to stay there. I also noticed Skype. Rating: 7/10 
Design: I see you used direct mode, and created objects with it. That was good. There are some one tile thin walls, though. Rating: 7/10 
Difficulty Balance: Note: You get a high rating for having medium difficulty and a low score for being too hard/easy. Ideal difficulty there are some hard places, like YOU ARE A PIRATE or the 2nd room of the Lab, but the rest is ideal. Rating: 9/10 
Glitch Amount: You exploited at least 4 glitches on purpose, which are necessary to clear the level, and that's bad level design. Also, there should be a separation between the "Chamber of trinkets" and the open area. Also,in the "Okay, You win" trinket, you could have put a warp token so that you don't need to die (create walls around it except above it, so that you get the trinket before you touch the warp token). Most of the scripts repeat. There are also the glitches I mentioned in other posts. Rating: 3/10 
Total rating: 14
/20
EDIT: Added ratings, difficulty balance and wrote more things.
FIRST OFF: The three missing trinkets are in the "Final zone/Ominous zone" and are placeholders, I'm planning on adding a notification after you get 10 trinkets to tell you where to go, or I'll use the gotoroom command (is that it?) that is used in Return to VVVVVV.
I need to know what these exploits are, and unless you're doing a no death run or something I don't see why I should remove the death trinket. If you're counting then just subtract 1 from your death count.
The upside-down wall moving thing IS an exploit I know of, and I wasn't planning on this getting featured or anything but I thought it was cool, besides there's pretty much no way you could mess it up because of the spikes unless you're TRYING to screw yourself over, in which case I'm not sure what to say. Conclusively, I can't figure out why but as soon as you take the warp token in "Ominous Crater", VVVVVV will crash. I'm not sure why, because I think my scripts work, unless you can't have a flash and a say command right in the room entrance.
Also the cool trinket notifier doesn't work. Will fix it, but it'll be less cool. Wait, there's no

? I can't really replace the

in the cliff face, sooooooo... I'll find the other

.