The object of the game is simple: As the music plays, circular notes will appear on the screen, and you must tap on them when converging circles overlap the notes. Occasionally, the game throws out "hold" notes that must be held down until they vanish, and "slide" notes that must be dragged into from outside of the note. Notes may also rotate, zoom, and scroll to where you must hit them; the result is what can be described as Osu! Tatakae! Ouendan with some elements of Camera Screw.
Tone Sphere can be purchased from the iOS App Store for a one-time cost of 1.99 USD or 240 JPY, with all updates are provided free of charge, while the Android version is available with ads that can be dismissed also with a one-time cost.
Tone Sphere provides examples of:
- Anti-Frustration Features:
- The timing windows on slide notes are looser.
- On iPhones and iPod Touches, the notes are slightly larger relative to the screen.
- Color-Coded for Your Convenience:
- The combo display that appears when you hit a note will flash purple on a Perfect, orange on a Great, and dark orange on a Way Off.
- When the marker color scheme is set to "Rhythm", notes will be colored pink if they fall on a quarter beat, blue on an eighth beat, yellow on a sixteenth beat, and purple on a triple beat.
- Damn You, Muscle Memory!: "otome" by suzutune also appears on another rhythm game, Cytus. Both games use ~2-minute cuts of songs, but the Tone Sphere cut and the Cytus cut vary, throwing off players who are used to one cut but not the other.
- Dynamic Difficulty: Inverted. The difficulty level for each chart is based off of the average star score for the chart. See Joke below to see what happens when a chart is made difficult to "fail" on.
- Easter Egg:
- Confirming chart selection with a quad-tap triggers autoplay mode, in which the game plays the chart for you. Getting to the results screen results in the performance comment "AUTOMATIC!"
- Entering "Sidesphere" as your ranking name triggers Side Sphere mode, in which the score and combo counters are turned 90 degrees, the idea being to turn your device in the same orientation.
- Entering "judgedelta" as your ranking name triggers judgedelta mode, which lets you adjust the timing windows to be harder or easier. Making the timing windows easier will disqualify your score.
- Everything's Better with Spinning: The camera likes to spin around on many charts.
- Gameplay Grading: On the surface, it looks like it's on a scale of 0 to 5 stars. However, earning 97.5% of the maximum "star score" will give you a 6th star. Earning stars raises your Sphere Level and unlocks new charts.
- Harder Than Hard: Above Hard difficulty is Expert difficulty, as well as the Spherical difficulty.
- Interface Screw: Some of the modifiers do this.
- Shakycam will cause the camera angle to tilt depending on your device's angle.
- Harlem Shake is similar to Shakycam, except the tilting happens uncontrollably and randomly.
- Stealth hides the notes, forcing you to rely on the converging circles to know where and when to hit notes.
- Pinhole shrinks the notes.
- Jumbo enlarges the notes.
- Sixth Sense Stealth hides both the notes AND the circles, forcing you to play the entire chart by memory.
- Cover is an inversion; it darkens the background, making it easier to see the notes.
- Joke Level: The "Spin Angular Momentum" charts. Both of them introduce exclusive "angle notes"; tapping a 45-degree note spins the camera 45 degrees, while tapping a 90-degree note turns the camera to another face of the chart. Both charts are also extremely trivial to clear, as only tap and hold notes contribute to the note count, but angle notes still add "star points", and if you put in even a little effort you will clear the chart; it's common to have all six stars before the song is even halfway done. Since the chart difficulty ratings are based on average player score, both charts also have a difficulty rating of zero.
- Licensed Game: A large majority of the tracks are licensed. However, Sta, a musician himself, also composes tracks that appear in the game.
- Nintendo Hard: The more difficult charts require heavy amounts of memorization to get decent scores on. Fortunately, the game comes with an autoplay feature.
- No Fair Cheating: Using the secret judgedelta modifier with an input higher than 1 (to make the timing windows looser) will disqualify the score you get with it.
- Rank Inflation: Star rankings are out of 5, but getting a near-perfect "star score" will give you a hidden 6th star.
- Scoring Points: There are two scoring systems at work, further detailed here:
- The first one is the one shown at the top-left corner of the screen during gameplay and is used to determine rankings. You gain points based on timing judgement, but some sections of songs have multipliers that make notes worth more points on getting a Perfect.
- The second influences your star ranking and clear status. Each note is worth up to 2 points depending on timing, regardless of section. You need two stars out of 5 (obtained with 50% of the maximum star score) to clear the chart.
- Sound-Coded for Your Convenience: The hit sound effects. Different variations of the hit sound you're using will play if you get a Great or Way Off instead of a Perfect. Due to flaws in Android that would render syncing hit sounds and the on-screen action impossible, the Android version forgoes them in favor of vibrations.