Dusty Dessert has a ton of problems. First of all, a desert is spelled with one s and dessert, like cake and ice cream, is spelled with two. Also I took screenshots of areas that were particularly bad and I'll discuss them below:
It's best to have blocks and platforms three to four blocks high. Here is a five block jump up to the platform, where the blocks are only two blocks above that. Since this is the first power up in the level, it shouldn't be that difficult to retrieve. This starts the level on the wrong foot, but there's more to follow.
This Ghost House block doesn't need to be here.
This is just flat out bad design. The difficulty is completely unbalanced, and is just hard for the sake of being hard. The level should get difficult gradually, but this is too much. There's no gimmick or trick, it's just trial & error until you make it past this section. Also when you enter the section for the second screenshot, it's possible to walk over the level so you should extend your walls and ceiling above the top of the level boundary. Also since the moving spike wall is way too fast and is relatively short, if (when) you die you can see it cut off when the whole layer passes by.
This isn't fun, and should never be done.
This is pointless platforming and it just gets in the way. These platforms shouldn't be there.
Check these links and apply them to SMBX, and play more levels before making more levels to pick up on better design:
http://marioleveldesign.com/
https://www.youtube.com/watch?v=e0c5Le1vGp4
Overall this level just isn't fun, and really isn't worth playing. Try and make levels that you would likely see in a Nintendo game to get a better grip on level design.
Operation Information 2.0 is marginally better. I like the concept and it was well put together, however there are some serious problems. If you defeat the green goombas out of order, it is not possible to progress because that green platform will activate and then despawn. Also this thwomp automatically dies:
Since this is a relatively short level that's all I have to say about the general design, but the boss design was terrible. You have three Rinka spawners firing off which - more often than not - kill the koopas thaw spawn infrequently that are supposed to be used on a moving mother brain. The player should never have to rely on AIs to progress in a level, and that's the only thing to do in this boss fight. Other than that there's minor grammar problems (I know you did the l33t speak on purpose that's not what I'm talking about) with the signs. This level definitely needs fixing up and would be much much better if other things were thought through.
Coral beach is okay for a first level, but again there's serious problems. First of all after completing the mission I jumped, accidently went to an instant warp, got warped, and the section I warp to has an exit warp going downard, but you didn't put instant warps along the bottom so I missed the bottom warp and just died for jumping. I wish I had a gif of how silly that looked. Also there's areas where you can walk above the level like here:
There's a glitch with a goomba that just gets stuck here resulting in an unfair death/hit:
Lastly, the color switches were pretty much pointless especially for this part:
This is now sort of a meta-review, but your level design quality is all over the place and you should really practice more and try to spot these flaws before submitting them. I hope this review helped and you're able to fix your levels up.
