Here is the full list of all 34 TETRAGUN achievements.
Complete a run using the Gatling Gun.
Complete a run using the Laser Cannon.
Achieve a score of 200,000.
Achieve a score of 300,000.
Achieve a score 400,000.
Use Bullet Storm 3 or more times during a completed run.
Eliminate 50 enemies affected by stasis in a single run.
Eliminate a Shield Piercer enemy while they are touching one of your shields.
Eliminate 8 enemies with a single laser.
Eliminate a total of 2,500 enemies.
Eliminate 10 enemies with a single disk.
Complete a run without firing more than twice before switching to another quadrant on extreme difficulty or higher.
Use Dual Blades 3 or more times during a completed run.
Eliminate a total of 25,000 enemies.
Complete a run without letting a single powerup expire on extreme difficulty or higher.
Have 6 foot soldiers on the battlefield at once.
After obtaining Groove Rock before wave red, complete the run without it being hit once on hard difficulty or greater.
Complete a run with all of your stats at 300% or greater while on hard difficulty or greater.
Complete a run with any stat at 800% or greater while on hard difficulty or greater.
Complete a run without using your ability on extreme difficulty or greater.
Use Overclock 3 or more times during a completed run.
Complete a wave without firing your weapon.
Complete a run using the Rocket Launcher.
Use Shield Generator 3 or more times during a completed run.
Complete a run using the Shotgun.
Use Stasis 3 or more times during a completed run.
Complete a run on nightmare difficulty.
Have 60 asteroids within your orbit at one time.
Complete a run while playing under a dog. Jk, complete a run with all of your stats at 100% on hard difficulty or greater. This achievement should be obtainable while playing under a dog though (not tested).
Complete a run after gaining at leat 75% stats from both Enemy Siphon and Shield Siphon on hard difficulty or greater.
Eliminate a total of 250 enemies.
Eliminate 40 invisible enemies in a single run on hard difficulty or greater.
Complete a run using the Disk Thrower.
Beat playtester Cody's highscore of 423,854