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Developer(s) Dean "peppy" Herbert
Platform(s) Microsoft Windows
Android (starting 2.1)
iPhone (App Store)
Windows Phone
Release date(s) September 16, 2007
Genre(s) Music
Mode(s) Singleplayer, Multiplayer

osu! is a freeware rhythm game originally for Microsoft Windows. It is written in C# on the .NET Framework. The game has also been ported to OS X, iOS, Android, and Windows Phone.[1] Its gameplay is based on commercial titles including Osu! Tatakae! Ouendan, Elite Beat Agents, Taiko no Tatsujin, beatmania IIDX, O2Jam, and DJMax.


Game levels are called beatmaps. In each beatmap, a song will play and different rhythmic hit elements (hit circles, sliders and spinners) will appear on the play field. Players must use a pointing device to manipulate these elements in time with the playing song's rhythm in order to earn points. The use of a graphics tablet in combination with a keyboard is common in osu!, although some players do use a mouse. Very few use a Tablet PC for playing osu with.


There are 5 default difficulties which are easy, normal, hard, insane, and expert. There is also a marathon tag that means maps tagged with this are over 5 minutes of drain time, and a "TAG2/TAG4" difficulty that means maps which must be played by two or four people at the same time. Content creators, beatmap designers can also give their own names for their difficulties.


The main objective when playing osu! is simply for players to hit, complete, and clear enough hit circles, sliders and spinners to keep their health bar, which drains at a steady rate throughout the game, above 0 until the song is over. More experienced players will often strive for a more specific and difficult goal, like improving their high score or grade on a particular map, usually by attempting to time their hits better and avoid as many misses as possible to increase combo multipliers.

A hit circle as it appears in osu!.

Hit circles[edit]

Also sometimes referred to as notes, hit circles are a common object on nearly every beatmap. When a hit circle appears, a ring, called the approach circle, will appear around it and begin to shrink. In order to score points from a hit circle, players must place their cursor over the circle and click the hit button as the approach circle touches the edge of the hit circle.


Sliders appear as two hit circles with a solid path, called a slider track, between them. As with hit circles, an approach circle appears at the beginning of a slider track, which must be clicked when the approach circle touches its edge. Unlike hit circles, however, after the start of a slider has been hit, a ball, called the slider ball, will begin to roll along the slider track, and players must continue to hold down the hit button and keep their cursor hovered over or near the slider ball until it has reached the end of the slider. Sometimes a slider end will have an arrow, called the reverse arrow, which means the player will be required to follow the slider ball back to its starting point.


A spinner is a large circle that takes up most of the play field when it appears. A ring like the approach circle of hit circles and sliders will also appear and begin to close on the spinner's center. Players must hold down the hit button and spin their cursor around the center of the spinner. As players continue to spin, the spinner gauge at either side of the screen begins to fill, and once it has been filled, the player will be notified that the spinner has been cleared. Continued spins after this and until the ring reaches the spinner's center will award bonus points.

Hits and misses[edit]

Hit circles, sliders, and spinners have different criteria to how they can be hit or missed, and to how points can be gained.

Clicking the hit button at the right time while the cursor is hovered over a hit circle or the start of a slider, or clearing a slider will earn a player points. In the case of hit circles, the points awarded are completely dependent on the timing of the hit. Sliders are generally considered more lenient, and as long as a player doesn't hit the start far too early or too late, collects all the slider ticks, and continues to hold the hit button and hover the cursor over the slider ball until it reaches the end, a maximum number of points are earned. The points awarded by a spinner are dependent on the number of spins completed. Additional spins after a spinner has been cleared will further increase the points earned. Successful hits will fill the health gauge a small amount.

No points are earned when an object has been missed. Hitting a hit circle too early or too late, failing to either collect any slider ticks or finish the end of a slider, or failing to fill the spinner gauge an adequate amount will result in a miss being added to a player's score. A miss, or missing a slider tick, will cause the health gauge to drop a small amount.


A combo multiplier is kept throughout the song. Upon successfully following an object (hitting a hit circle, hitting a slider end or slider tick, clearing a spinner, etc.), the multiplier is increased by 1; upon a failure (missing a hit circle, missing a slider end or slider tick, not filling a spinner an adequate amount, etc.), the multiplier is reset to 0. This multiplier is then multiplied by several factors including the difficulty of the played beatmap and "mod multiplier", user-applicable multiplier resulting from activating gameplay-altering mods, which is then multiplied by the base score of the hit to get the score of the hit. To be more precise, the score formula of a hit is:

Score of a hit = Base score of a hit * (1 + combo multiplier * difficulty multiplier * mod multiplier / 25)


osu! has several difficulty modifiers that can alter the gameplay. These mods are categorized into three groups:

Difficulty reduction[edit]

These mods reduce the difficulty (for example, by disabling failing so a player can play even when the health bar reaches zero), but at the expense of reducing the score multiplier.

  • Easy reduces the approach rate, overall difficulty, HP drain and increases the circle size.
  • No Fail makes it so that the player cannot fail.
  • Half Time decreases the BPM to 75% of the original.

Difficulty increase[edit]

These mods increase the difficulty (for example, by applying a "flashlight" so only a small region around the cursor is visible at any time), for an increase of the score multiplier.

  • Hard Rock decreases the hit circle size, flips and makes the notes upside down, increases the overall difficulty, increases the approach rate, and increases the HP drain.
  • Sudden Death makes it so that when the combo breaks, the player fails.
  • Perfect makes it so that the game will restart when the player drops under 100% accuracy.
  • Double Time increases the BPM to 150% of the original.
  • Nightcore is the same thing as double time, but pitch and the background beat are affected.
  • Hidden gets rid of approaching hit circles and makes it so that the hit circles vanish after appearing.
  • Flashlight makes it so that the visible part of the screen is very small. At 100 and 200 combo, it became increasingly smaller, but it returns to the original size if the combo is broken.
  • Fade In hides about 1/4 vision above the conveyor and vision continue to be decreased until the 500th combo.


These mods are the mods that don't apply to other categories. These mods make the play "unranked" and scores not being kept (excluding "1K"-"9K", Co-op and "SpunOut" mods).

  • Relax makes it so that the player only needs to move the cursor.
  • Auto Pilot makes it so that the player only needs to click.
  • Spun Out makes it so that spinners are automatically done.
  • Auto allows the player to watch a perfect play of the beatmap (with some exceptions).
  • Cinema is the same thing as auto, but the player can only see the background and storyboard.
  • Target Practice turns the game into a game as described by the title, and the speed is determined using the "BPM".

Other game modes[edit]

osu! features three special game modes that are accessible in the mode selection of the play menu: Taiko, Catch the Beat, and osu!mania. These game modes allow a different style of gameplay from the standard play mode.


The Taiko mode is based on Taiko no Tatsujin, another rhythm game which involves hitting drums to the beat of a music piece. Taiko mode does not require the use of the cursor except for browsing the beatmap list and the pause menu. Instead, only clicking is required, which is done on a keyboard. However, the osu! community has found various ways of supporting a Tatakon or DrumCon controller intended for the Taiko no Tatsujin PS2 games. Usually, an external script is used to map the controller input to keys on the keyboard. A PlayStation to USB Controller bridge is required to adapt the controller for a computer.

When playing the Taiko mode, red and blue beats, as well as long yellow drumrolls (with an appearance similar to a slider) will scroll across the screen – the player gets more points for the more hits they can achieve. In the original Taiko no Tatsujin games, the red beats are referred to as "dons" and the blue beats "kats". The red beats represent the Taiko (drum) center and the blue beats the rim. Spinners are also present in the Taiko mode. Towards the left of the screen is a stationary circle. A player must hit the key(s) corresponding to each coloured beat when a beat passes under this circle. Key configuration can be reviewed and changed in the Options menu, under Input.

To hit the red beats, players must hit one of the two Taiko inner hit buttons. For blue, a Taiko Outer hit button must be pressed. When a large beat passes under the circle, pressing both corresponding keys will earn players extra points. When a long beat passes under the circle, players should tap to the rhythm in order to earn points. When a spinner appears, they must alternate hitting the inner and outer hit buttons until the number at the bottom reaches 0.

Catch the Beat[edit]

This mode puts the player in control of a character (named Yuzu) holding a plate above their head, with the objective of catching fruits falling from the top of the screen.

Regular beats on a map are converted simply to fruit falling straight down. Sliders have one fruit at each end of the slider and a trail of juice drops leading between the ends. Large juice drops are the equivalent of slider ticks, while small drops add extra points to the score and affect accuracy. Spinners become fruit falling en masse from the top of the screen; the player does not need to catch all of the fruit, although catching more fruit will earn them more points.

Screenshot of "osu!mania."


Osu!mania is a mode similar to Beatmania IIDX and DJMax where players need to press keys bound to several columns according to the music. As the music plays, notes are falling from the top of the screen in several columns whose number depends on the map. As a note reaches the bottom row of some column, the player is expected to press the key bound to that column to clear the note.

A special set of mods is available in osu!mania, namely 1K, 2K, 3K, 4K, 5K, 6K, 7K, 8K, 9K, Co-op, Fade-In. Usually beatmaps are meant to be played by a certain amount of keys set for the beatmap; however, using one of these special mods (1K-9K) can change this amount of keys for a score reduction.

This mode was made public on September 30, 2012.


The game uses player designed "beatmaps", which are the files containing the actual gameplay data. These are created using an in-game editor, allowing the user to pick any song they like and produce beats for it. Beatmaps for specific songs can then be shared through an in-game uploader directly linked to the main site. Players can then provide feedback for the beatmaps, referred to as a "mod", usually suggesting some means of improving its quality. After the author has modified the beatmap according to the tips it received and the Beatmap Nominators are content with its quality, they may nominate it for ranking. Beatmaps must then undergo a seven-day trial period in the "qualified" beatmaps section, after which they will be moved to the "ranked" beatmaps section. Qualified maps have a high chance of returning to pending if an issue is found by a member of the Quality Assurance Team.[2] Statistics for each ranked beatmap are maintained on the osu! website. Scores for each ranked beatmap are totaled to determine a player's ranked score, which determines a player's score ranking.

As of April 13, 2015, over 300,000 beatmaps have been created, out of which over 10,000 have attained ranked status. The number of ranked maps gradually increase as the Beatmap Nominators rank newly submitted maps.[3][4]


On June 3, 2008, multiplayer was added to the public release (b335).[5] Multiplayer consists of a central lobby displaying available rooms, and current online players. Rooms are created with the "New Game" button. A game begins when all players in the room are labeled as "Ready" and the host clicks start. The Multiplayer game is made up of the normal components as a Single Player osu! game, but with the in-game scoreboard displaying the current rankings of the players in the room. All play modes (including Taiko, Catch the Beat and osu!mania) are available in multiplayer mode, as well as a variety of scoring rules, such as osu! Standard Score, where the highest score wins, or osu! Standard Accuracy where hitting the notes perfectly seizes the top spot. Players are also able to play tag co-op where the room works as a team to complete the song as each player is given certain beat clusters to hit, 1 player at a time. As of release b593a, Tag Team mode has been introduced where players are sided on two teams (Red and Blue) and work as one to win.

Critical reception[edit]

The game has been featured in several magazines and websites.[6][7] The reception has generally been positive, with the biggest complaint being that playing osu! with the mouse takes a long time to get accustomed to.

Non-PC Platforms[edit]

As of November 2008, an iPhone/iPod Touch osu! port was announced and was released to the general public on January 2009 via Cydia repositories.[8]

An official App Store version of osu! entitled osu!stream was released on 08/01/2011.[9] osu!stream does not allow for user made beatmaps to be played, instead allowing only a select number of songs that are purchasable from an in-game store.

At the Malaysia Comic Fiesta 2013 in Kuala Lumpur, peppy released his new osu!tablet.[10]

A version of osu! for Windows Phone 7 and 8 devices called osu!WP has also been released.[11]


An official version in the Apple App Store was added for the iPhone/iPod Touch called osu!stream.[12] This version of the game does not include custom beatmaps. It instead has both free and paid beatmaps available for download in the ingame store.

On January 3, 2014 osu!stream was removed from the iOS App Store for copyright reasons.[13] However, it was re-added to the iOS App Store on January 28.[14] Since the copyright infringement letters, beatmaps with links to beatmania IIDX or Skrillex have been removed, although they can be found through external sources.[15][16]

osu!stream has three gameplay modes:[17]

  • Easy: Slow beats, and it is impossible to fail.
  • Stream: This mode is unique to osu!stream. This mode causes the gameplay to switch between "streams", or different difficulties in a single game based on the player's performance.
  • Expert: Can only be unlocked if the player has achieved the ranking of "A" or better in stream mode. In this mode, gameplay is difficult with beats appearing faster, more stacking beats, more connected beats and faster drain of the health bar.


The community includes over 7,000,000 registered users, with a total of over 3.60 billion ranked plays.[18]


osu! offers perks to players who contribute $4 or more. Supporters can download beatmaps directly on the osu! client, and can automatically download from spectator or multiplayer matches as well as several other perks.[19]

See also[edit]


  1. ^ http://www.windowsphone.com/en-us/store/app/osu-wp/83be2e91-48ca-4cfe-9a0d-851b01e62d42
  2. ^ "Beatmap Listing". Retrieved 2015-04-13. 
  3. ^ "Beatmap Listing". Retrieved 2015-04-13. 
  4. ^ "Beatmap Listing". Retrieved 2015-04-13. 
  5. ^ "osu! Public Release b335". Retrieved 2014-09-10. 
  6. ^ "Free PC Ouendan/EBA emulator hits public beta". Retrieved 2014-09-10. 
  7. ^ "Osu! - Download". Retrieved 2014-09-10. 
  8. ^ "osu! for iPhone and iPod Touch". Retrieved 2014-09-10. 
  9. ^ "osu!stream on the App Store on iTunes". Retrieved 2014-09-10. 
  10. ^ "osu! panel at Comic Fiesta 2013 - YouTube". Retrieved 2014-09-10. 
  11. ^ "osu! WP". Retrieved 2014-09-10. 
  12. ^ "osu!stream". Retrieved 2014-09-10. 
  13. ^ "ppy - Apple IP infringement policy woes (aka where is osu!stream?!)". Retrieved 2014-09-10. 
  14. ^ "osu!stream on Twitter: "osu!stream is once again available on the app store! hoping to submit a new update over the coming week some new stuff :)."". Retrieved 2014-09-10. 
  15. ^ "Removal Request on Konami's Contents (Bemani Series)". Retrieved 2014-09-10. 
  16. ^ "DMCA Notice (Skrillez / GrayZone)". Retrieved 2014-09-10. 
  17. ^ http://osu.ppy.sh/wiki/Osu!stream#New_Modes_to_replace_the_difficulty difficulty levels of osu! stream. Retrieved March 2, 2013
  18. ^ "osu!". Retrieved 2015-11-26. 
  19. ^ "Supporting osu!". Retrieved 2014-08-17. 

External links[edit]