Osu!, or osu! Is a free-to-play and open source rhythm game. Originally created in 2007, the game has been updated to include more game modes. Dean Herbert, known as "peppy" [1] in game, took inspiration from rhythm games such as Osu! Tatakae! Ouendan and Elite Beat Agents as he created osu!.

File:Osu!Logo (2019).svg
osu! logo
AuthorDean "peppy" Herbert
Initial ReleaseSeptember 16, 2007
Game GenreRhythm Game
Coded withC#

Overview edit

The current version of osu! includes four game modes: osu! (or osu!standard), osu!taiko, osu!catch (or osu!ctb), and osu!mania. Each mode can be played through the use of beatmaps, which are user-created representations of songs through the use of various objects. During gameplay, players are tasked with “hitting” the objects based on the game mode.

Beatmaps edit

Beatmaps are user-created representations of music or other mp4 files through the use of various objects. Beatmap creators can adjust various aspects of the beatmap’s gameplay, from the judgment windows to the mode of gameplay [2].

Game Modes edit

osu! edit

In osu!, players use the cursor to click or provide a keyboard input to hit objects that appear on screen. Various objects include circles, which requires a single click; sliders, which requires the player to click and hold the object while moving the mouse to follow the slider; and spinners, which requires the player to hold an input while moving the cursor around the center of the screen in circles.

Judgment and Health edit

All objects in osu! are judged by the difference in time between the object being hit and when the object needs to be hit, or whether or not the player spins the cursor around the screen enough times (in the case of a spinner). osu! does not feature a standard judgment across all beatmaps. Instead, it is set by the beatmap’s creator. osu! features four ratings, listed as “miss”, “meh”, “good”, and “great” in the source code. During gameplay, all ratings other than “miss” increase the player’s health, while a “miss” decreases the health bar [3]. A beatmap is considered failed if the player’s health bar is completely depleted, while a pass is given when the player reaches the end of the beatmap, no matter the current position of the health bar.

Scoring edit

Every object, excluding slider ticks award the player 0, 50, 100, or 300 points based on the accuracy of the player relative to when the object needs to be hit [4]. However, all consecutive objects that are hit can add to a combo count, while misses reset the combo counter. During gameplay, score is calculated as sum of points awarded by objects multiplied by the combo counter. At the end of the beatmap, a letter rank is also given to show the performance of the player during the beatmap.

Ranks and Conditions for osu! beatmaps [5]
Rank/Grade No misses One or more "miss"
SS 100% accuracy N/A
S > 90% "great"s, and < 1% "meh"s N/A
A > 80% "great"s > 90% "great"s
B > 70% "great"s > 80% "greats"
C > 60% "great"s > 60% "great"s
D < 59% "great"s < 59% "great"s

osu!taiko edit

In osu!taiko, players use the keyboard to hit objects that scroll horizontally to the left side of the player’s screen. Objects include red (“don”) and blue (“katu”) small and larger circles, drumrolls, and spinners [6]. The names of the red and blue notes are similar to the notes’ names in Taiko no Tatsujin, which is the inspiration for this game mode [7]. Unlike Taiko no Tatsujin’s drumrolls, osu!taiko requires the player to press keys at regular intervals to gain the most possible points from it [8]. Spinners, unique to osu!taiko, require the player to alternate between a red and blue circle input.

Judgement and Health edit

osu!Taiko removes the “meh” judgment rating that osu! uses, and only reduces the player’s health on missed objects [9]. Unlike other game modes, players start with no health, and must increase their health by the end of the beatmap [10]. The beatmap is considered a pass when the player completes the beatmap with at least half of the health bar.

Scoring edit

Because of the three judgment ratings, a “great” rating rewards 300 points, meaning that “good” and “miss” ratings give 150 and 0 points, respectively [11]. Large circles, large drumrolls, and the ends of spinners reward double the points depending on the judgment. Unlike osu!, osu!Taiko does not reward as many points based on the total combo count, and rewards more points based on the beatmap’s calculated difficulty [12].

osu!catch edit

In osu!catch, the player uses the keyboard to control a character that catches fruit that falls from the top of the screen. There are various fruits that can fall from the top, but most fruits serve the same purpose. Exceptions to this include bananas, which give bonus points; fruit drops and droplets, which are transitions between fruits, similarly to sliders in osu!. Players are able to make the character dash, in the event that the character does not move quickly enough to catch the fruit.

Judgment and health edit

Due to the nature of the game mode, the only judgment ratings are “miss” and “perfect” [13]. All objects receive one of these two ratings depending on whether or not the player catches the fruit. While all of the fruits receive a judgment, bananas are the only fruits that do not decrease the player’s health. Like the other game modes, health is lost when fruits are missed. An osu!catch beatmap is considered passed if the player reaches the end of the beatmap without letting the health bar be completely depleted.

Scoring edit

Because osu!catch only uses two judgment ratings, each object will be worth their full point values or nothing. Caught fruits are worth 300 points, fruit drops are worth 100 points, and the smaller droplets are worth 10 points per droplet. osu!catch uses a similar scoring calculation to osu!, where the points awarded are a product of the point value and the current combo count.

osu!mania edit

In osu!mania, the player uses the keyboard to hit two types of notes that scroll vertically to the top or bottom of the screen, depending on the player’s choice. While there are only two types of objects, being notes and hold/long notes, beatmaps can be set to be played with one to nine columns of notes. While selecting an osu!mania beatmap, the player can see how columns will be in use by the number of corresponding columns, followed 'K', or keys.

Judgment and Health edit

osu!mania features the highest amount of judgment ratings, at six ratings. In order from lowest to highest point value, the ratings are: “miss”, “meh”, “ok”, “good”, “great”, and “perfect” [14]. Standard notes receive one of these six judgments based on the accuracy of the note being hit. However, hold notes receive a judgment based on the initial hit and release of the note. In gameplay, missed objects and objects with the “meh” rating reduce the player’s health bar, while other ratings will increase the player’s health. In addition, holding a hold note increases the player’s health over time, for the duration of the hold note. Like osu! and osu!catch, a beatmap is considered a pass when the beatmap is completed without having the health bar be completely depleted prior.

Scoring edit

osu!mania features a more complex scoring system than the other three modes. Even though the in-game ratings for “miss”, “meh”, “ok”, “good”, “great”, and “perfect” are miss, 50, 100, 200, 300, and a rainbow 300, respectively, the objects are almost always not worth the points listed. osu!mania is also the only game mode where the the score has an upper limit, being 1 million points. This maximum score is divided into two categories, being the base score and bonus score, split evenly. While the base score is from the accuracy of the hit object, the bonus score is determined by many factors invisible to the player, such as a multiplier based on the accuracy of previous objects [15].

References edit

  1. "Peppy's Profile," accessed September 26, 2019, https://osu.ppy.sh/users/2
  2. "Beatmapping," accessed September 24, 2019, https://osu.ppy.sh/help/wiki/Beatmapping
  3. "OsuJudgment," accessed September 22, 2019, https://github.com/ppy/osu/blob/master/osu.Game.Rulesets.Osu/Judgements/OsuJudgement.cs
  4. "osu! Scoring," accessed September 24, 2019, https://osu.ppy.sh/help/wiki/Game_Modes/osu!#scoring
  5. "osu! Grades," accessed September 24, 2019, https://osu.ppy.sh/help/wiki/Game_Modes/osu!#grades
  6. "osu!taiko Gameplay Basics," accessed September 24, 2019, https://osu.ppy.sh/help/wiki/Game_Modes/osu!taiko#gameplay-basics
  7. "太鼓の達人とは" Taiko no Tatsujin official site, archived from the original on 13 June 2014. accessed September 26, 2019, https://web.archive.org/web/20140613072124/http://taiko-ch.net/about/
  8. "osu!taiko Hit Objects Judgement," accessed September 24, 2019, https://osu.ppy.sh/help/wiki/Game_Modes/osu!taiko#hit-objects-judgement
  9. "TaikoJudgement," accessed September 22, 2019, https://github.com/ppy/osu/blob/master/osu.Game.Rulesets.Taiko/Judgements/TaikoJudgement.cs
  10. "osu!taiko Health Bar" accessed September 24, 2019, https://osu.ppy.sh/help/wiki/Game_Modes/osu!taiko#health-bar
  11. "TaikoJudgement," accessed September 22, 2019, https://github.com/ppy/osu/blob/master/osu.Game.Rulesets.Taiko/Judgements/TaikoJudgement.cs
  12. "osu!taiko Hit Objects Judgement," accessed September 24, 2019, https://osu.ppy.sh/help/wiki/Game_Modes/osu!taiko#hit-objects-judgement
  13. "CatchJudgment," accessed September 22, 2019, https://github.com/ppy/osu/blob/master/osu.Game.Rulesets.Catch/Judgements/CatchJudgement.cs
  14. "ManiaJudgment," accessed September 22, 2019, https://github.com/ppy/osu/blob/master/osu.Game.Rulesets.Mania/Judgements/ManiaJudgement.cs
  15. "osu!mania Score," accessed September 24, 2019 https://osu.ppy.sh/help/wiki/Game_Modes/osu!mania#score