Here is the full list of all 21 Scrap Attack VR achievements.
Finish Wave 20 on any Difficulty
Shoot 50 Enemy Projectiles
Scrap 100 Enemies with Critical Hits
Finish One Game
Score 100,000 Points in One Game
Scrap Big Red
Finish Wave 15 on Easy
Scrap 100 Enemies
Hit 5 Enemies at the same Time
Scrap an Enemy from a Large Distance
Shoot 5 Enemy Projectiles
Scrap 10 Enemies with Critical Hits
Complete the tutorial
Pop a Jellofish
Finish 10 Games
Finish Wave 15 on Medium
Finish Wave 15 on Hard
Scrap 1000 Enemies
Teleport 100 Times
Shoot a Target
Shoot a Gnome