Full list of all 12 Galaga Legions DX achievements worth 200 gamerscore. It takes around 4-5 hours to unlock all of the achievements on Xbox 360.
Cleared Area 2!
Cleared Area 1!
Cleared Area 3!
Cleared Area 4!
Cleared Area 5!
Cleared Area 6!
Cleared Area 7!
Cleared Area 8!
Cleared Area 9!
Cleared Championship!
Completed all Time Attacks!
Cleared all areas on hard difficulty!