Beat Hazard is Asteroids on LSD. You are a small ship in the middle of space. Astroids are flying about and other space ships are trying to kill you. Every level in the game is different because it is randomly generated by a freely chosen song. The more beat in the music, the stronger your weapon becomes, but at the same time more enemies are spawning. You weapons, the enemies' weapons, and explosions are all very colourful, and at hectic times you can barely see the screen from colours.
When I bought the game I was afraid it would be like Bullet Candy, which I didn't like. But it's not! This game is fun, actually really fun, and especially since you decide your own difficulty by chosing songs - slow songs being the hardest. If you have a few minuts and fell like playing a casual game while listening to some tunes, then I would highly recommend this game.
Most of the achievements are fairly simple, and when you get the Veteran achievement (Accumulate 10 hours of play) you'll probably have most of the others as well. At first you'll think it will be impossible to get 1 million points in one track, but after you level up, you'll find 1 million points in one track is a lousy run. The hardest achievement is probably Survival Champion! (Reach 20 Minutes in Survival Mode), but with the right choice of music it's doable - a megamix is a good choice, make sure there's no quiet moments in the songs, nor at the beginning or the end. You'll most probably get the Boss Slayer achievement (Kill 8 bosses in 1 game) while playing survival.