Here is the full list of all 23 Featherpunk Prime achievements.
Completed the tutorial.
Completed First floor.
Take down Guardian 1.
Take down Guardian 2.
Take down Guardian 3.
Take down Guardian 4 and destroy Cybirdroid.
Activate the checkpoint.
Destroyed 10 times.
All Sector 1 collectibles collected.
All Sector 2 collectibles collected.
All Sector 3 collectibles collected.
All Sector 4 collectibles collected.
Every collectible in every sector collected.
Complete the Boss 1 without dying.
Kill 500 enemies.
Kill first sentinel.
A funky hat for F-Droid.
Kill 100 enemies during Overdrive.
Less than 10 health pickups used.
Complete the game with killing all Guardians the first time.