Well, I've seen worse first levels.
The layout feels largely incidental, very likely made up on the fly as the author was checking out what JCS can do. There's a sense of sections, where one concept is immediately dropped forever as another one comes up. This might be seen as a positive, as it technically keeps things fresh. However, given the nature of these gimmick, it doesn't feel intentional to me in any way, just classic "my first JJ2 level" shenanigans.
First section starts you off having to collect coins to progress, and you have to do this while falling. This is most likely why the level is supposedly "4 Jazz", but I played Lori who also has a copter ears move and even so I found it impossible to collect all of them on the first try (and you do need all of them). So you have to go back, and the method to do this feels counterintuitive, mostly because it's placed near a tree. JJ2 experience says the tree branches are one way platforms, but not this time, and it almost feels like intentional padding.
Here the player is thrown into what feels like JJGBA's shop intermissions, except everything is free. Worth noting is that this establishes that ammo is only provided in this level as part of puzzles and progression. I don't like this in general, as I feel utility is secondary to combat value for JJ2 weapons and should be mostly limited to secrets, but even aside from my personal preference this level does the cardinal sin of not respawning things necessary for progression. Instead, whenever there's a task you can fail, you're provided with suicide spots. Even in vanilla JJ2, there's a quicker and more elegant way to do this via CTF bases, so I'd recommend that next time if you don't want to delve into scripting just yet. Then again, JJ2+ death pits are easy to place even in JCS.
The next section I can only describe as things copied and pasted almost at random, just to fill space and play time. This is probably where jjturbo9 figured out how to copy things. The regular path is supposedly very hard, and well, it's not a cakewalk with all the bees, but you also get plenty of carrots and because these are the same repeating chunks of tiles you know what to do after you've climbed the trees once. As for the other path, I'm confused if the "secret" is a secret at all, given how obvious it is and that the level outright tells you about it twice. I guess not, since it's more or less assumed as necessary for the next section. The highlight here was having to get a Float Lizard to follow the player, and then avoiding smoke rings on the way up. I know I've seen this combination of ideas before, but not a lot.
It's at this point that the level uses the Sugar Rush mechanic as a means of progression. It's a novel idea, but because it's not scripted in any way, it doesn't do its job. Any character other than Jazz can just blast through, and even with Jazz it's entirely possible to tank enough hits to speed to the other side. Out of all the things in the level, this is where Angelscript would most come in handy.
The worst path though is the maze. On the technical side of things, it's actually the most impressive part of the level: generous use of new tiles, a frog puzzle that feels quite advanced for someone's first JJ2 level, and a decent sense of player jump height. However, all of this doesn't help that this is simply a maze through and through, something not very well suited for JJ2. If it was populated more interestingly, perhaps. But right now it's only a bit more palatable than Queen of Board (which sucks and I'm not open to discussion about it). The biggest problem is the concept of wrong turns. Sure, they're clearly marked. But it's still a ridiculous obstacle, with a punishment incommensurable with the kind of mistake you're doing. Furthermore, the Trigger Zones aren't properly placed – it's very easy to end up stuck in one of the appearing blocks, and then the only way out is cheats or level reload. Near the end, you get an option to backtrack. It's fool's gold. Whatever you might've missed, the level has so few items that it's definitely not worth having to go through the entire maze again to get back on track. A shortcut that opens up once the maze has been completed once would be nice.
And finally there's the boss arena. Is this a spoiler? There's no story, so I don't think so. The area is absurdly large considering the boss itself is stuck on a small platform. Well, at least you can't go so far away that the boss would despawn, so points for that I suppose. Miniscule ammo amounts in the level don't matter either, since you get the best powerup in the game just handed to you.
Now, as a final note, I'm not the type of person to complain that "you didn't use the tileset conversion that I'd worked so hard on, weeehhhhhhh" – but the yet another new Diamondus edit included with this level feels extremely superfluous. It's just FawFul's old edit with a few tiles changed, and most of them are really unnecessary. I recommend trying out the custom MLLE level editor, which lets you use vertically flipped tiles with a single key press; you wouldn't have to include every tile you're flipping in the tileset. You can also easily place a player character sprite onto the sprite layer and color it like a multiplayer skin however you'd like, it's just a few script lines! I know it feels impossibly hard at first, but it's really simple once you check out a few existing JJ2+ examples. Also, placing flowers on tree branches is certainly a… choice. Mistletoe, I guess?
jjturbo9, I hope my review and its rating doesn't discourage you from making more JJ2 levels. Rather, my intention is to give you an incentive to strive to be better, to learn more and especially learn from other custom levels. It's a long way to the top (if you wanna rock 'n' roll), but since you already went the extra mile to make your first level bigger and better designed than most first levels that land on J2O, I'm certain you can get even better!
Single player, by 
