Here is the full list of all 30 SSS222: HyperSpace Playtest achievements.
Get 100 points in Arcade Mode
Get 1k points in Arcade
Get 10k in Arcade Mode
Die 100 times
Destroy 1k comets
Destroy 500 mechanical enemies
Block a projectile with a Saber
Achieve 666 score in Hardcore Mode
Achieve 2077 points in Classic Mode
Get 150 points in Meteor Madness
Collect a Power Core
Collect each type of powerup once
Fire over 10k times
Survive for 1 minute when on low HP
Trade for the first time
Trade for over 20 times
Customize any element of your ship for the first time
Customize all elements of your ship
Spent over 15 minutes in Sandbox Mode