In Amplitude, the player controls a ship (referred to as a "Beat Blaster") moving down a path of varying shapes and lengths, containing up to six tracks. Each color-coded track corresponds to a different aspect of the song, such as percussion, synth, bass, or vocals, and contains a sequence of notes. As the player hits buttons corresponding to the note placement on the track, the notes activate a small portion of the track. If the player successfully activates enough notes in sequence, the track is "captured" and the section will play automatically for a number of bars, freeing the player to capture another section.

Capturing sections also releases "sonic energy" that keeps the Beat Blaster in motion. The primary object of the game is to capture a sufficient amount of sections to reach the end of the song. If the player continually misses notes, the energy meter empties until the game is over.

There are several different powerups available to the player to make gameplay easier. Powerups are gained by activating a series of specially shaped and colored notes. Such powerups allow immediate capturing of tracks, doubling of points scored, slowing down the speed of play, and jumping into freestyle mode (which allows the player to riff to the music, gaining points without the difficulty of playing predefined tracks).

The player achieves a high score in the game by quickly moving from track to track without a break as each is completed, increasing a point multiplier. Tracks with more notes are worth more points, so choosing those over simple tracks is advantageous as well.

The game is structured as a series of levels, each containing a number of regular songs, a "boss" song, and a bonus song available when the player reaches a sufficient aggregate score for the level.

UNLOCKABLES

Annie

Successfully complete the Blastlands bonus song under the Mellow or higher difficulty setting.

Bat Gal

Successfully complete the Beat Factory Boss song under the Brutal or higher difficulty setting.

Bat Lad

Successfully complete the Metaclouds bonus song under the Normal or higher difficulty setting.

Biggie

Successfully complete the Metaclouds bonus song under the Mellow or higher difficulty setting.

Bot Girl

Successfully complete the Beat Factory bonus song under the Normal or higher difficulty setting.

Bug

Successfully complete the Beat Factory Boss song under the Insane difficulty setting.

Cyclops

Successfully complete the Elektro Kore bonus song under the Insane difficulty setting.

Demon Dave

Successfully complete the Metaclouds bonus song under the Brutal or higher difficulty setting.

Diabolical D

Successfully complete the Elektro Kore bonus song under the Brutal or higher difficulty setting.

Disco Marv

Successfully complete the Blastlands bonus song under the Brutal or higher difficulty setting.

Evil Motomatic

Successfully complete the Elektro Kore Boss song under the Insane difficulty setting.

Fred

Successfully complete the Neotropolis bonus song under the Mellow or higher difficulty setting.

Goggle Bot

Successfully complete the Beat Factory bonus song under the Insane difficulty setting.

Grondor

Successfully complete the Beat Factory Boss song under Normal or higher difficulty setting.

Happy Fun Girl

Successfully complete the Beat Factory Boss song under the Mellow or higher difficulty setting.

Hotpants

Successfully complete the Metaclouds Boss song under the Normal or higher difficulty setting.

Kim

Successfully complete the Blastlands Boss Song under the Mellow or higher difficulty setting.

Kong

Successfully complete the Beat Factory bonus song under the Brutal or higher difficulty setting.

Larry

Successfully complete the Blastlands Boss song under the Insane difficulty setting.

Lazy Jay

Successfully complete the Elektro Kore Boss song under the Normal or higher difficulty setting.

Levar

Successfully complete the Metaclouds Boss song under the Mellow or higher difficulty setting.

Little Tony

Successfully complete the Blastlands Boss song under the Brutal or higher difficulty setting.

Mad Melvin

Successfully complete the Neotropolis bonus song under the Insane difficulty setting.

MC Mike

Successfully complete the Blastlands bonus song under the Normal or higher difficulty setting.

Here is a gameplay video: