Single player, by 
BollyWorld is a rare example of both the aerial boss battle and the level where choice of character truly matters. The basic premise is that you are fighting Bolly, but instead of a solid ground from which to attack him, you are given a series of sucker tubes that continually shoot you up into the (horizontal and vertical) center of the arena. To aid you in reaching him, two float lizards respawn from beneath the arena, and if you can successfully shoot them, you can potentially use their copters to take you up above Bolly where you may stomp him repeatedly until eventually he gets hidden inside a wall and you fall down to begin the whole process again. There are also a couple of carrots respawning at the top to make the fight more endurable.
To complicate all of this, the level is filled with belt events, alternating in direction by row, so Bolly’s missiles wobble a little and whenever he or the float lizards stop moving (to fire at you) they are carried inexorably off towards one or another of the walls. This makes stomping Bolly much harder, naturally, and even when you do succeed in shooting down a float lizard, their copters will suddenly go zooming off to the left or right where you will have to work hard to catch them. It’s a clever addition, one which you begin to come to terms with after the first few deaths.
You should definitely expect to see the Continue? screen a lot, because the carrots don’t respawn very quickly and it’s non-trivial to reach them anyway, and Bolly will only get in a good position for stomping every so often. Many of my deaths came about by running into shot-down lizards while zooming through the sucker tubes at the bottom — remember to stomp those as well, or shoot them from the corners in hopes of carrots. The bottom corners can be good ways of shooting down lizards, since you’re not in the air at the time, but they’re especially nasty places to be swarmed by Bolly and his long chain of spike balls, which is much harder to deal with when you can neither uppercut nor sidekick them all away in a heartbeat.
To add to all of this, there is a secondary, hidden strategy that you will probably have to use JCS to discover. There’s a lot of bouncer ammo at the top, and some trigger crates and a powerup are below the arena, as what appear to be random eyecandy to give the impression of lights or something. However, and the level gives no indication of this, the blocks underneath the bottom corners of the arena are secretly destruct scenery, which you can use the bouncer ammo to destroy after making a trip up to the top of the level to collect some. From there you have to destroy all the trigger crates, though the small height of the area means that this secondary strategy should be attempted only by Spaz. If successful, the area with the carrots post-crate-kicking also allows access to an airboard, which renders the rest of the boss fight if not trivial, at the very least much simplified. As a tradeoff for this reduced challenge at the end, it’s much harder to navigate the arena with a double jump than copter ears. The Jazz option of simply fighting the boss feels a lot better put together.
Graphically, the level is… well, functional. Again, there is no real way of knowing how to reach the trigger crates short of JCS, but moreover, there’s just not much in the way of eyecandy. The background is a series of starfields, invoking the “city of lights” aspect of the title, and the sky seems to have some sort of strange window effect going on that I don’t really understand. Either the tileset is holding the level back or the author is holding the tileset back. Perhaps both. I understand that too much eyecandy would serve to obscure gameplay, but something closer to a middle ground would definitely have been possible.
Bollyworld is a very clever idea, coming even with events specific to different difficulty modes (which I confess to not having dried), although the complexity of the arena makes it difficult to know when one is exploiting a bug vs. when one is playing the level as it is intended to be played. If I stomp Bolly while he is almost completely hidden behind a wall while waiting for him to finish firing, am I supposed to be able to do that? It’s hard to tell. With some better graphics, this level would serve as a great example of an Idea that was translated to level form with apparently minimal sacrifice.
