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