Here is the full list of all 55 Serious Sam VR: The Last Hope achievements.
Complete a mission on hard without taking any damage
Complete all level 20 arenas
Complete all level 15 arenas
Complete all level 10 arenas
Complete all level 5 arenas
All perfect hard
All perfect serious
Fire the orbital psi laser
Unlocked the entire skill tree
All 5 gold medals
All 5 platinum medals
Deploy a dummy decoy
Activate money time
Activate rage
First perfect hard
First perfect serious
Complete a level 20 arena
Deploy a defense turret
Activate invulnerability
First gold medal
First platinum medal
Complete a level 15 arena
Detonate a serious bomb
Deploy a drone squad
Step into the arena
All 5 wood medals
All 5 bronze medals
All 5 silver medals
All perfect tourist
All perfect easy
All perfect normal
Defeat the Earth giant
Unleash an army of domestic spiders
Defeat the giant Swamp Hive
Complete a level 10 arena
Complete a level 5 arena
Fire an orbital laser storm
Fire an orbital laser strike
Fire the orbital stun field
Activate time stop
Defeat the Shaanti dragon
Use the portable medkit
Activate serious damage
Unlocked a skill
Defeat the giant anomaly
First wood medal
First bronze medal
First silver medal
First perfect tourist
First perfect easy
First perfect normal
Defeat the giant mummy
Complete a planet without healing
Complete a co-op game
Step into the battlecruiser Saratoga