Single player, by 
This level is honestly not that good. I’m assuming Spaz18 added around 4-5 extra points to his score because of the fact that this was Puffies’s first level.
I’m trying to be as fair as possible when I say that this level is in the same league as “Uterus’ Castle”. Puffie has a good focus on his level that keep it from being painful to play, but it reeks too much of bad design to be recommended for playing.
The number one thing thing Puffie gets wrong is overpowering the player. You get far more ammo than you need, and oftentimes there is a Powerup monitor right next to a cache of ammo. The number two thing that is wrong here is letting the player know too much. A few bits of discovery are absolutely ruined by textstrings. The one right before the highjump, for example, is high unnecessary since the blue spring is right in sight. There is another one, placed by mistake I’m assuming since the same message can be found in an out-of-the-way text sign a little ways ahead, that spoils a secret gemstomp completely. The second instance of this rather offputting text (i.e. the one that is a littleways off and on a sign) is actually welcome since it rewards the player for going out of their way by clueing them into a secret they might of otherwise skipped over. The first instance of this textstring however is right in front of the secret, which diminishes the fun. The third major thing that Puffie gets wrong is the extremely dull boss arena that is used for the robot boss. To be fair, a decent arena for the robot boss is hard to get right, so my suggestion would be for Puffie to have used a different boss.
Onto the more broader subjects, the level design is extremely linear. There are bits where it gets somewhat clever but there are too few of these and they’re never clever enough. Design is far too open for any of the enemies used to be effective at rabbit-roasting, and enemies that do work in open areas are seldom used if at all. The design would work had Puffie made varying paths that were still rather linear (ala Green Hill Zone in Sonic 1) or had the player go through multiple areas with a clear, well-thought out minor puzzle/enviroment interaction along a sole path (ala Marble Zone in Sonic 1 or the game Whiplash) with good filler material inbetween. Puffie does neither and the level feels dull to play because of it. By expanding his level designs to be either slightly non-linear, or more focused on challenging the player, Puffie will be able to create quite decent levels for a fledgling designer. As it stands, this level shows Puffie has potential (its overall “feel” is much better than the usual trite uploads from first time designers) but it just isn’t all that fun.
Second broad subject is the eyecandy which is rather basic. The design of the level hurts the eyecandy as Puffie cannot flex the tileset all that much on layer 4. The background layers are used very poorly, and at times background objects appear to be floating in midair.
While Jazzed Lab is a good effort for a first level, and is backed by a better handling of the JCS that other fledgling designers like jackflash don’t have, it isn’t all that good, far too short, and somewhat dull.
