Here is the full list of all 37 Thyrian Defenders Playtest achievements.
Get 40000 Kills
Kill Mega Brain and rid the galaxy of the Exodon
Get an S ranking on any level at Master difficulty
Max any upgrade on the Titan
Reveal the entire map
Roast 10000 enemies with Redwing
Get 20000 Kills
Get all medals on any stage
Unlock and fight aside all sidekicks
Get to Master difficulty on any stage
Destroy every asteroid in Asteroids
Get an S ranking on any level
Hit 1000 enemies behind you with Trex
Get to the boss without getting your sidekick hit
Get 5000 Kills
Get 6 speed upgrades during a run
Collect every plasma container in the game
Beat Krilis on Master without the help of a sidekick
Beat Tibula on Master without using any specials
Stay unharmed in Hyperspace β without using a shield
Beat Crypto without touching a bubble
Avoid any wind element in Draconia on Veteran difficulty or higher
In Pyrex, stay over lava for at least 100 seconds without getting burned
Destroy every enemy and object in Hyperspace γ
Get the unharmed target for all difficulties on any stage
Beat Onslaught in Boss Rush mode
Get to the boss without losing your sidekick 50 times
Get all Medals
Collect 350,000 GP in total
Fully upgrade the Titan
Play the same level 50 times
Break all stunballs without getting stunned in Hyperspace α
Beat a stage without collecting any GP
Use 10 or more specials in one run
Stun 5000 enemies with Thexter
Reach 666m in Survival Simulation 7