Here is the full list of all 15 Amped 3 achievements worth 1,000 gamerscore. It takes around 15-20 hours to unlock all of the achievements on Xbox 360.
Impress the required number of bystanders in each area of Northstar to Own the Mountain.
Finish Act I of the story to unlock the Snowbird resort.
Earn a Gold Medal for ALL challenges and media callouts.
Earn any Medal for ALL challenges and media callouts.
Impress the required number of bystanders in each area of DC to Own the Mountain.
Congratulations! You defeated the Baron!
Build 200+ terrain park objects.
Finish Act IV of the story by rescuing the rest of the crew.
Impress the required number of bystanders in each area of Laax to Own the Mountain.
Impress the required number of bystanders in each area of Valle Nevado to Own the Mountain.
Finish Act III of the story by rescuing Weiner Boy and gaining access to the secret C.A.I. area.
Impress the required number of bystanders in each area of Snowbird to Own the Mountain.
Finish Act II of the story to unlock Valle Nevado.
Travel 10+ kilometers on a snowmobile.
Earn 1,000,000+ points in sledding scores.