100 Likes: The most useless type of map in the game, some players just upload these to get the corresponding icon by waiting for people to like them.
Glitch levels: They are just used to test glitches in the game.
Collab levels: Most of these levels aren't playable, as when the player starts, it gets teleported up high, not allowing the player to see the level.''
Challenges: Given names like "Wave Challenge" or "Zobros Challenge", they give short doses of an extremely difficult challenges to advanced players.
Creator Contests: Popular among the famous creators, this is when a creator creates a short portion of a map and asks other players to finish the map.
v# Levels: Harder remakes of main or user created levels. This very famous trend was started by Neptune and continued by several players.
Art Levels: These levels focus more on the design rather than on the gameplay itself. Some of them include HyperArcade and Optical Illusions. On 1.9, it was very difficult to make because preview mode did not exist at that time and it would only be noticed when above standard.
Sunset Levels: Another type of art styled level, where most of the colors are black. Most sunset levels use a gradient background
Retro Levels: Levels that are computerized, these are usually pixelated or use sharp animation. The introduction of Retro Text in Update 2.0 makes this more realistic.
Impossible Levels : These levels have so far not been completed by any player at all, because they have been either hacked to verify them or a new update has prevented a mechanic from working properly. Silent Clubstep is an example.
Map Pack levels: Self-explanatory, these are the most popular levels because they can be used to get more achievements in the game by completeing them and are featured in map packs.
If ...... was Level 1: Also self-explanatory, these are taken from a very hard level like Cataclysm and makes them easier. Also known as ...... Easy levels. This trend is now continued on by Jukaras.
MLG Levels: These levels always have MLG songs, that usually get removed from NG until few time. Sometimes have flashing lights and have letters written on it. MLG Christmas is example.
Effect Levels: Levels with many effects, which became very popular in 2.0. They are often very very laggy for low end devices. Because of this, most effect levels have a "Low Detail" mode, which removes most of the laggy decoration.
Troll levels: These levels are maps full of fake obstacles and invisible objects. Many of them with stars are rated as insane. Can't Let Troll, Troll Machine and Stereo Retroll are some examples.
Darnoc-Style Levels: Relatively fast paced gameplay combined with unique ground objects and pulsing objects.
Neon-Style: Either a lot of flashing lights using blending, or something more along the lines of the wave section in Adventure Fantasy.
Old-School: Quite self-explanatory, it is a level which uses an old style of blocks and decorations. An example is Dear Nostalgists by TriAxis.
Invisible Levels: Invisible versions of another level (mostly main levels) Examples: Invisible xStep and Invisible Clubstep (both by Cyclic)
Fast Levels: Fast versions of levels (also mostly RobTop levels) like Fast Back on Track.
Reversed Levels: Self-explanatory, they are levels that are reversed which means, the level begins from the last part of it instead of the first part. Example is Well Then.
Clubstep-Styled Levels: Are levels that are inspired from the 14th main level, Clubstep. They mainly use 1.6 blocks and "monsters" that either have eyes made from jump rings or pulsing objects. Notable examples are Clubstep v2, Club Impact, Ice Carbon Diablo X, Deadly Clubstep, and zStep.
Disliked Levels: Very self-explanatory, are levels that are disliked due to bugs/glitches, bad design or gameplay, or either are mistaken as impossible. Some disliked levels are impossible. Each disliked starred level is previously to 1.9.
Film/Movie Levels: Also self-explanatory, are levels that are introduced by TriAxis in update 2.0, they are films/movies that are made by move trigger, alpha trigger, etc. Some examples are Wysteria by TriAxis and Be Gone, Mr. Gawne by Jyle14.
Paint Levels: copies of the main levels, but made with drawn-style objects and a sheet-lines-like background. This trend was started with Chokureload's Page One until Hysteric made the trilogy: (Paint Madness, Paint On Track and PaintGeist).
Videogames' parodies: levels that mime, as realistic as possible, some videogames, that are usually 1980's Nintendo videogames (PacMan, Super Mario Bros) or games for smartphone or PC (Flappy Bird, Minecraft, Traffic Racer). An honorable mention is Syobon Action by Sweetdude.
Noob-styled levels: levels made by famous creators like Zobros, who mime the typical level of a beginner child player (main songs, clusters of messy objects, strange color combinations, absence of decorations). They make these levels just for fun, to kid their fans. They usually add specially ungrammatical descriptions to exaggerate.
Shitty levels: copies of popular demons with the default colors (blue BG and ground, white objects) and without any decoration. They are heavily nerfed in many cases, such as Shitty Sonic Wave or Shitty Bloodbath.