Theatrhythm Final Fantasy All-Star Carnival is an arcade rhythm video game and the successor to the Theatrhythm series of rhythm games that were originally released on the Nintendo 3DS. The game features revamped arcade controls, improved graphics, cooperative play, and songs and characters that were not featured in previous versions. As with many modern arcade games, All-Star Carnival is network-enabled and is continuously being updated with new content.
The core gameplay consists of activating triggers in time with iconic songs from the Final Fantasy series. The main interface of each All-Star Carnival arcade cabinet consists of two large buttons that are flanked on either side by a hemisphere-shaped joystick. In order to active red touch triggers, the player must tap one of the two central buttons with the indicated timing. Similarly, green hold triggers can be activated by holding either one of the two central buttons. To active yellow slide triggers, the player must flick one of the two available joysticks in the indicated direction.
Unlike previous games in the series, All-Star Carnival sometimes requires players to active two triggers at once. For example, occasionally two touch triggers will appear in a vertical stack. This indicates that the player should press both of the central buttons at the same time. Additionally, some slide triggers will have two arrows pointing in the same direction. This indicates that the player should flick both sticks in indicated direction at the same time. These new combination triggers greatly increase both the complexity and difficulty of the game when compared to previous entries in the series.
Both Field Music Sequences (FMS) and Battle Music Sequences (BMS) make a return; however, the gameplay of these two song types, in terms of the party's actions, have been combined. Rather than exploring during FMS songs and battling during BMS songs, the player's party now regularly alternates between exploring and battling regardless of which type of song type is being played. A new type of song called an album is introduced. Albums are medleys that contain short segments of five other songs. Albums are unique in that they alternate between BMS-style and FMS-style gameplay depending on whether the current song segment is originally from a BMS or FMS song. Playing an album counts the same as playing two BMS/FMS songs. All-Star Carnival currently contains no Event Music Sequence (EMS) songs.
One of the largest additions is cooperative play. In online mode, each player is automatically matched with other players from around the world. In local-multiplayer mode, players can instead partner with others that are using neighboring All-Star Carnival cabinets within the same arcade. When players are matched, their parties are combined to form a sortie. Parties in a sortie automatically work together to take down monsters and support each other. There can be up to four parties in a sortie. Some items affect the entire sortie, rather than just a single party.
Most BMS songs have the option of being played in pairs mode. In this mode, two players work together on the same arcade cabinet in order to complete the song. Each player controls one button and one joystick. One player is responsible for activating the triggers in the top two lanes, while the other player must activate the triggers in the bottom two lanes.
All-Star Carnival contains several new options that were not available in previous titles. Players can now adjust the scroll speed of triggers, change the color of triggers, and adjust the volume levels for both battle sound effects and trigger sound effects. Two new difficulties are introduced: beginner and transcendent. The beginner difficulty is meant for players who are new to rhythm games, while the transcendent difficulty is meant to challenge highly experienced players.
The game features over 60 playable characters, with nearly all characters from the handheld games returning. The player has access to a large roster of characters by default, and they can unlock new characters by collecting the crystal shards that are randomly dropped by defeated boss-class monsters. There are two types of crystal shards: light and dark. Each of these two types comes in four different colors. Collecting one of each color of light crystal shard will allow the player to unlock a protagonist. Collecting one of each color of dark crystal shard will allow the player to unlock an antagonist.
All-Star Carnival features a wide variety of songs from the Final Fantasy series, as well as a small selection of songs from other Square-Enix titles. Players have access to a large selection of songs by default, and they can unlock additional songs by purchasing them using sound medals. Sound medals are randomly dropped by defeated boss-class monsters. Most songs cost 5 sound medals to unlock, though some required 10 medals instead.