GOTTAGOFAST

GOTTAGOFAST (GGF) is one of the Cheat Codes in The Metronomicon. 
GGF is a special, hidden mode where the objective is to complete the base game's 50 song playlist in one sitting, but, when compared to NOPEEBREAKS, has an entirely different scoring metric - time taken to complete the songs.
Thus, instead of playing through the full lengths of each song, your goal is to quickly defeat all the enemies in each song - including the Minibosses. If you ever die or fail to defeat the miniboss in any level, you immediately lose the mode.
Enemy level is scaled to the average of your party members' levels.
==Beginner Strategy==
If you're just getting your feet wet in the mode, start out with all the equipment and maximum-leveled (50) characters at your disposal! It's honestly best to find a strategy that works for you first, before making radical tweaks to various aspects.
A good starting party would comprise of:
Sara - Labcoat
Ralf - Berserker
Gwen - Protector
Wade - Warrior
This was the party first used by Ryntrussell in the first match of the Metronomicon Speedrun tournament. Space out Sara and Gwen from each other by putting a character in between, put Shock, Bash, Reckless and Attack at T1, and continue cycling through the T1s. Sara and Gwen's stunning attacks will effectively stunlock the enemies, meaning you won't be damaged much, if at all. But, for safety's sake, equip Shine, and stick Awe and Grin at T2. Your main goal is to pump out the damage with Ralf and Wade, just be careful with the perma-Blind status that Ralf's Reckless will bring up.
At this stage, Team Attack choice shouldn't matter too much - you won't go too wrong with Explosive Bumrush or Critastrophe.
While viable, this is slightly limited in the fact that your main damage source is just Primary Abilities and it doesn't take elemental weaknesses into account. To fix this, try out this build:
Gruver - Druid
Violet - Exploder
Gwen - Protector
Wade - Warrior
This strategy was debuted by powfordamage in match 6. While Violet represents a better means of element-countering, the key to this build lies in Gruver's Gift. Stick that at T1 and, whenever you get to his turn, always cast it, since it makes Secondary Abilities proc significantly more often. With Wade's Clobber and Violet's Choke now being triggered by Gift and Fresh Mountain Air, you can really start to increase your damage output significantly (plus, because Shine is also triggered, you don't need a healer either).
==Advanced Strategy==
Once you've got your feet wet in the mode, it's time...for level manipulation. I know, I advocated same levels for simplicity earlier, but if you really want to extract more speed, you need to make the enemies weaker. Level manipulation is thus the best way to do this.
Take the build used by powfordamage above, but instead of level 50 characters:
Gwen - Level 48
Wade - Level 48
Violet - Level 48
Gruver - Level 39
The odd level differential is due to benching Gruver and NOT buying the Workshop upgrades (specifically the gym) that increases the Experience gain for benched party members. But why level 39? That's when Gruver learns Fresh Mountain Air, so he can really supplant the other characters with a LOT of Secondary Ability beats. Plus, since he isn't being used offensively, downgrading his level would make the most sense, so Gwen, Wade and Violet would be facing off against ((48+48+48+39)/4) = level 45.75 enemies.
Probably the most drastic level differential ever observed, courtesy of AthrendFyre:
Gwen - Level 28
Wade - Level 50
Sara - Level 28
Ralf - Level 50
With this, Gwen and Sara gain incredibly low levels. You'll have to change up your playstyle when creating savefiles by completing levels, in order to make sure they don't gain so much EXP, while letting them gain just enough for Sara to learn Refresh. Wade and Ralf then become your main damage dealers - level 50 characters facing off against ((50+50+28+28)/4) = level 39 enemies. That's a HUGE differential!
Lastly, the currently most optimal strategy would be to combine aspects of the aforementioned strategies and get the best of both worlds:
Sara - 27
Wade - 50
Violet - 50
Gruver - 39
There's multiple ways to effectively utilise the strategy. You can opt for a slightly safer route (powfordamage's method) by using Wade to attack as per normal, but changing up Violet's attack so she does enough damage to kill the enemies...or you can take an almighty risky method (AthrendFyre's method, using an ability championed by MonStahLer) by putting Saving Throw in T1, purposely dropping your health to low to increase its power, and clobber through enemies with it. (For the latter, you'll need a failsafe - The Necronomithong.) Just remember to skip Sara whenever any of your attackers are ready to act - use Sara only if you urgently need a heal, even though at this low level she wouldn't do much anyway.
At this stage, you're already going so fast, Critastrophe and Explosive Bumrush wouldn't be as effective - instead, Buffotronic Prime would be the best choice. After that, kit out your team with damage-increasing equipment (The Master's Judgement, Dare Devil's Horns) and you're good to go!
As of the Slay The Dance Floor expansion, there exists new Passive Abilities that can speed up times even more. With the best level-manipulation party above, only Wade and Violet's passives are truly essential. It is entirely possible to struggle along in Endless Mode farming up enough Battle Points to buy these passives.
==On level manipulation==
Because characters gain more Experience the more enemies are killed in a level, ideally you'd want to survive a level long enough to just finish defeating the miniboss or boss, and no more after that. This means you need a certain degree of passiveness in your level play. Try to use the progress bar in the top right as a gauge, and keep your pace roughly around the red bar.
Bench the characters that you require to be underlevelled. They will still gain EXP, just not as fast as your active party members. Blitz through story mode, skipping to the boss level once unlocked, and use any uncompleted levels or Daily Challenges for the final levels.
Do NOT ever replay levels if you miss out on any equipment you need. Backup your save file before the level and restore it if you fail to get the item required. This is especially true of The Ultimate Slap and Fuzzy Hand Endazzlers.
Of course, getting the Training Room before your party is fully assembled is a no-go.
==Recommended Equipment==
*Sara - Depending on level, you can either use damage-increasing equips, or The Necronomithong and Creepy Mechano Ring.
*Ralf - Time Enshortener (if you put Reckless in T1), The Master's Judgement
*Wade - Puuuumps, The Master's Judgement
*Gruver - Fuzzy Hand Endazzlers, Fresh Moontain Air
*Gwen - A Gentle Kiss, The Ultimate Slap
*Violet - The Master's Judgement, Dare Devil's Horns
As a note, equipment that gets stronger the longer the song lasts isn't advised, since you'll be completing the songs too quickly for them to give any sort of benefit. Keep this fact in mind when choosing equipment.
==SEED****==
SEED**** (SEED followed by any four keys) is a different cheat code that shortens the GOTTAGOFAST mode to a randomly-selected bunch of 10 songs depending on the seed. The mechanics remain the same, however - beat the songs as fast as possible without dying or failing to defeat the boss.
For tournament build history, see Seeded Speedrun.
==Trivia==
*This cheat code was the method for how The Metronomicon Speedrun Tournament, entitled WEINER 2 - Winners Excite the Internet! Note Eater Racing, was held.
*Since then, an item, named after the winner of the tournament, AthrendFyre, was created. The item itself is built for completing songs quickly, and could potentially be used to lower times in this mode.
*SEED**** will be the method for how WEINER 3 will be held. The tournament is structured differently, with contestants competing in best-of-3 rounds (and parties that have won one round being locked out from further use in the match). During the tournament, builds are locked to level 50 characters, so there will be no discussion on level manipulation.
==External Links==
*The Metronomicon Speedrun Tournament (in reverse chronological order)
*The Metronomicon on speedrun.com (includes an optimal level manipulated savefile)