Here is the full list of all 12 RoboBlitz achievements worth 200 gamerscore.
Beat the game without purchasing any upgrades (Master Technician)
Fire the Space Cannon and kill the MegaNoed (Master Technician)
Earn 500,000,000 points
Collect all the Upgradium
Earn 250,000,000 points
Obtain both armor upgrades
Earn the Tractor Beam upgrade
Earn 100,000,000 points
Earn the Point-to-Point Beam upgrade
Obtain any weapon upgrade
Obtain any movement upgrade
Beat any level