Here is the full list of all 25 StretchBot achievements.
Stretch begins his quest.
Buy all of Stretch's upgrades.
Reach 9999 parts.
Buy a heart.
Kill 50 enemies.
Kill 100 enemies.
Kill 500 enemies.
Kill 1000 enemies.
Break 50 boxes.
Break 100 boxes.
Break 500 boxes.
Break 1000 boxes.
Break 50 walls.
Break 100 walls.
Break 200 walls.
Break 500 walls.
Hit the top of the finish line 10 times.
Collect 10 gears.
Collect 25 gears.
Collect 50 gears.
Collect all 63 gears.
That machine won't be bothering the rebels no more.
Finally those weird twins are gone.
It seems like the planet is safe for now.
Defeat a boss without taking any damage.