|Creator||GREEN, Constar, DeadPool17, Geometry B3ar, Digitulized, GooglyBear, Marzj, Nakase, KAoz, Herzilo, RNatos|
Madhouse is a 1.9 Insane Demon mega-collaboration created by GREEN and 10 others creators. It features difficult timings, many fakes, and requires skill in each and every gamemode. The level sticks to a grayscale scheme. It also uses 1.9-styled backgrounds and blocks, and many spinning objects. However, it features 2.0 coins as well. Due to this, it is generally considered an Insane Demon but in some cases a Very Hard Demon.
The level starts with ConStar's part, a difficult timing based cube part with many fakes. Then it goes into DeadPool17's part, a similar cube part but at double speed. It goes into an auto cube part leading into the drop. It then enters Geometry B3ar's part. It starts with a dual mini wave part at triple speed, leading into a cube section with many timings and fakes. Then there is Digitulized's part, which is a similar triple speed cube. It then has a tight ship part, leading into a swingcopters section and a tight slow wave. It then leads into GREEN's part, which is a triple speed cube followed by an auto wave and a difficult ship part with several orbs. Then there is a triple speed ball with some timings, followed by a relatively simple cube part. Then there is GooglyBear's part, starting with a difficult ship segment with an orb, followed by a fast-paced ball part with some timings. It then has a difficult UFO with many gravity portals. Then there is a slow tricky cube part as Marzj's part, followed by a tricky dual mini wave. It then has a tricky ball section, followed by a slow Necropolis-styled cube part. Then there is a tight ship segment, leading into Nakase's part. Nakase's part uses fake spikes, and starts with a slow wave part. It then has a rather tight ship part, followed by a timing-based ball part. It then has a mini UFO with several gravity portals. Then there is KAoz's part, starting with a ship with a tight section and several purple orbs. It then has a very tricky dual cube section with timings and tricks, which will require memorization to pass. It ends with a tricky UFO with several gravity portals. Herzilo's part starts, with a tight ship part with several synced gravity and speed portals later on. It then has a rather tight wave part, followed by a timing-based ball. It then has a cube part with one timing jump and several blue orbs that need to be pressed. The last blue orb in this part is hidden. Then there is RNatos's part, starting with a moderately tight ship, leading into an auto cube and a UFO with several gravity portals. The next ship is tighter with a gravity portal, followed by a double speed tight wave. It goes mini where the player avoids several spikes, and then there is a tricky timing-based cube part, and then the level ends. It shows the word "GG", as well as the names of all the creators.
- Order of collab members: Constar, Deadpool17, B3ar, Digitulized, GREEN, GooglyBear, Marzj, Nakase, KAoz, Herzilo, Rnatos (11 members).
- This level was not featured but rather being rated.
- The original level was uploaded by Constar, but it was verified with a secret way.
- GREEN nerfed the original level to verify it.
- The level was made in 1.9 and was later added coins in 2.0 Update.