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 reached the third level without losing a life.
You played in an online multiplayer game.
You scored 350,000 points.
You finished the game.
You scored 250,000 points.
You killed 30 wolves.
You defeated the third level boss.
You scored 150,000 points.
You defeated the first level boss.
You got fully altered without missing a White Wolf.
You collected a Spirit Ball.
You started the game once with each difficulty setting.