From the developer's website:
Welcome to a new experience in gameplay mechanics: Beat Hazard
Gameplay Powered by YOUR Music!
Experience your music collection like never before with this intense music driven arcade shooter. Each of your songs will have its own unique ebb and flow based on the music.
Power up your spaceship and watch as the music boosts your firepower. Unleash hell on the enemy ships when you max out with weapon pickups!
Beat Hazard seamlessly mixes the love of gaming and music. Together they become greater than the sum of their parts.
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Unique music driven gameplay
Gameplay possibilities as vast as your music collection
Go Head to Head in local 2 player mode
or work together with local 2 player Co-op mode
Can you last a whole album in Survival Mode?
25 Achievements
Take on the all new super boss ship
Power up and unleash the deadly Beat Hazard weapon
Rank up to an Elite rated pilot
Includes a kicking rock album to get you started
Files types supported: mp3 / wav / ogg / flac / aiff / wma
Note: iTunes / aac / m4a are supported via a $1 download