A disease has broken out across the nation, zombifying millions. For unexplained reasons, the virus only seems to affect orchestra students, and the only cure is the "sweet, melodious sound" of the trumpet. "It's a stupid story with plenty of holes," said Ninkancho's founder, "but who cares? Trumpet master race!"
As with many app-style games, the goal is to get a high score. However, in addition to the single-player mode, two players can team up for a separate high score in the multiplayer mode, where they have a shared combo point pool and more enemies to deal with.
Players use or to run, crouch, and jump, and to move the camera. or can also be used to jump.
Holding or makes the player character raise and start to play their trumpet, producing "damaging" soundwaves. However, doing so drains the chops meter, which only fills back up when not playing, and slows the character to a slow march when moving. With no chops, your character cannot play well enough to do any good.
While playing the trumpet, , , and face buttons can be used as virtual first, second, and third valves, respectively. Pressing them to play the pitches on the bottom screen's sheet music will award combo points, as will hitting several "enemies" with a single soundwave, though failing to hit any with just one wave will reset this meter.
Infected violinists, percussionists, and so on will continuously spawn from slightly off-screen, with poor, off-tune playing on their respective instruments as an attack. They can be cured of the disease by hitting them with just one or two soundwaves, at which point they will make a grateful expression and run off.
The game will also spawn the occasional mute or lip balm, the latter of which instantly refills the chops meter when touched.
Mutes appear at random in the stage as power-ups that, like real-life mutes, change the behavior, timbre, and color of the trumpet's soundwaves. They are equipped and discarded by pressing .
- Straight mute: A stuffy-sounding, conical mute held in place by three simple pieces of cork. It makes the trumpet's sound travel a longer distance at the cost of amplitude and power.
- Cup mute: This cardboard mute has a cup on the end, hence the name. Soundwaves will boomerang in a sort of sideways-teardrop shape with this mute equipped.
- Harmon mute: No stem spawns alongside this mute, but the sound is still fine without one. Two waves will be created whenever you play with it.
- Plunger mute: We can only hope this is a new plunger. Notes played with this mute in will move upwards slightly before arcing downwards, as if affected by gravity.
- Bucket mute: Any soundwaves produced with this mute clipped on will move at a slight downward angle for a while before quickly uppercutting in a homing attack. However, only one wave can be made at a time until it is discarded.