Full list of all 11 METAGAL achievements worth 1,000 gamerscore. It takes around 0-0.5 hours to unlock all of the achievements on Xbox One.
Watch the intro without skipping it.
Complete the tutorial level with GAL.00.
Collect 1 gear.
Collect 2 gears.
Collect 3 gears.
Die for the first time.
Fall of a level.
Die by spikes.
Rebirth with a gear.
Reach a checkpoint on any level.
Defeat any of your GAL sisters.