Full list of all 12 Altered Beast achievements worth 200 gamerscore. It takes around 1-2 hours to unlock all of the achievements on Xbox 360.
You finished the game.
You started the game once with each difficulty setting.
You scored 350,000 points.
You scored 250,000 points.
You defeated the third level boss.
You defeated the first level boss.
You killed 30 wolves.
You scored 150,000 points.
You got fully altered without missing a White Wolf.
You collected a Spirit Ball.
You played in an online multiplayer game.
You reached the third level without losing a life.