Here is the full list of all 50 Galactic Arms Race achievements.
Find 100 Isotopes.
Kill 1,000 Pirates.
Kill 1,000 Aliens.
Kill 10 Blobs.
Find 10 Isotopes.
Kill 10 Pirates.
Kill 100 Pirates.
Kill 10 Aliens.
Kill 100 Aliens.
Kill 1 Super Elite.
Kill 10 Super Elites.
Kill 1 Blob.
Fire 1,000 shots.
Fire 10,000 shots.
Collect 10 Isotopes.
Collect 100,000 Credits.
Die 10 Times.
Obtain double xp from a high level kill.
Get denied experience from trivial kills.
Modify a weapon using the Weapons Lab.
Achieve maximum Isotope fitness.
Kill 100 Super Elites.
Kill 100 Blobs.
Kill 1 Player.
Kill 10 Players.
Kill 100 Players.
Fire 100,000 shots.
Fire 1,000,000 shots.
Collect 100 Isotopes.
Collect 1,000,000 Credits.
Collect 10,000,000 Credits.
Die 100 Times.
Join a squad and kill a max level player.
Obtain level 100.
Obtain level 200.
Kill something level 1,000 or higher.
Get killed by someone who is infected.
Obtain an Autonomous Drone.
Enter a PvP Zone.
Achieve Maximum Rank.
Fill a squad with four players.
Win an arena match.
Kill an opponent while you are dead.
Achieve 100k Damage per second.
Kill a player less than half of your level.
Collision full speed with another player.
Teleport or warp exactly onto another player.
Kill one Geonoid.
Kill ten Geonoids.
Kill 100 Geonoids.