Tartarus

Tartarus (formerly known as Silent Akbar) is a 2.1 unrated collaboration created by Riot, Aurorus, EndLevel, Cyclic, Hinds, Aquatias, Salaxium, Komp, Azuler, and Vermillion. It is a hacked demon that is designed to be almost humanly impossible. It was uploaded by Riot to challenge the entire community to see who could legitimately verify it before he retires from the game. Riot thinks it may be someone not known or someone who is not playing seriously as of today. Whoever does will receive a shoutout from Riot, although this prize was invalidated for a short time due to Riot's YouTube channel being terminated, but Riot now has a new channel and the prize is therefore up again.

Gameplay

 * 0-23% (Vermillion): The level starts with a very pixel-perfect quadruple spike jump. After that, the player encounters a very inconsistent jump orb-spam which he/she is required to hit the jump orbs at the last second, also there will be another jump orb that he/she must hit at the end of the jump orb's hitbox. Following that is a tight normal speed ship sequence with a gravity portal that can really throw you off. Then, the player enters a minor mini cube orb-spam is required some minor timing. After that is one of the hardest parts of the first section of the level. The spikes is nearly touch each other and it is not much spaces. Next, the player enters a difficult mini ship sequence that features gravity changes and the spikes are tighter than the one in Bloodbath. You will change into a normal ship later, but it still required some tricky tight ship. The UFO segment afterwards is harder than it look because spikes is placed at buggy position that need a little timings. Then, the player enters a cube section that is pure-memorization, with no timing required and is easy to remember. The drop has a little break, but make sure that you remember which jump orb in which portal you should hit because it will kill you if you don't hit the right orb.
 * 24-35% (Aquatias + Riot): Then, the player will transition into an extremely difficult triple-speed mini ship sequence that is very tight with jump orb timings and gravity switches that will really throw off the player. When you get past that, a small section of tight wave and a UFO timing after that are not insanely hard like the first one, but still need some decent timing.
 * 36-40% (Komp):  A chill part of ball start Komp's part and then another ship sequence that is insanely tricky with more jump orb timings and gravity switches.
 * 41-47% (EndLevel): After that, player will enter a normal cube section which features some late timings. The straight fly after that is more insanely tight because a switch portal in the middle of the straight fly.
 * 48-53% (Salaxium): After a horrendous transition of the ship, there is a small spam cube part that usually in a impossible level. Then, the player enters an extremely difficult half speed swing copter section that many considers to be impossible in 60Hz. Timing of the cube after that is similar to the one before the swing copter.
 * 54-63% (Azuler): A UFO part that is very tight after that start Azuler's part is also need practices and spam skill. The mini ball part after that is not better which is similar to the UFO. After that is ANOTHER SWING COPTER part, but it not that hard as the first swing copter. After a buggy transition, a mini ship straight fly part is tight and harder than the normal ship because it is harder to control the small ship. A small section of normal tight wave ended Azuler's part.
 * 64-81% (Hinds): Hind's part start off with some minor mini cube jump and orb timings. The mini UFO follow by is have weird spam since you need to have three clicks in just 0.5 seconds. A small orb click of the mini cube and a mini ship four block straight fly that is easier because it just 0.3 seconds since it's a triple speed. The mini ball after... Well, it is switch speeds, switch from mini to normal pretty usually and it is need practice A LOT. A tight mini wave after that is awful since you just finish a tight ball part. Another mini cube jump orb timing and the player will enter a near-impossible triple speed straight fly that is the spikes it at the end of its hit-boxes. Some memorization cube and orbs timing and small mini UFO pink orb spam, after that is some weird ball timing and jump orbs. Small mini ship section is easy and not that hard like the one before that and you will go in a mini UFO section that looks like you can jump, but you just need to hit the orbs as the player went through the UFO. A tight straight fly follows by that. Some weird mini cube timing and jump orbs end Hind's part.
 * 82-83(?)% (Aurorus): Aurorus's part starts with a hard mini ball segment that features tricky timings and jump orb spam.
 * 84-87% (Salaxium II): After that is Salaxium's part which is a mini UFO segment with pink orb timings, insanely tight spaces, and jumps that all require good timing. A mini ship sequence that you need to maneuver it perfectly is also a hard challenge.
 * 88-92% (Komp II): Komp's part starts with a pretty decent triple speed cube timing and jump orb spam. His part is finished after the player has enter one of the most tight space wave segments ever.
 * 93-100% (Salaxium III): Salaxium's part starts with a triple spike. The ship after that is not that bad, the cube timing also just one click. The wave after is as tight as the one in Komp's part. A small cube orb click, and finally the SUPER TIGHT ball and SUPER LATE timing is the end of the level.

Trivia

 * This has caused some controversy, as some think it was wrong to use NoClip to verify the level, like Cinci, who was verifier of Innards (a level said to be harder than Tartarus).
 * Sea thinks that Tartarus is not rate worthy.
 * The current legitimate world record on this level from 0% is 91% achieved by Mullsy, he also achieved 41-100% at some point.
 * After Riot's account was terminated, he created another account and said that he would still give a shout-out to the victor of this beast.
 * In Greek mythology, Tartarus is the deep abyss that is used as a dungeon of torment and suffering for the wicked and is the prison for the Titans.