Here is the full list of all 37 High Noon VR achievements.
Kill 100 enemies with rifle
Make two headshots with one bullet
Spend $2000
Kill 250 enemies
Destroy 100 destructibles
Score kill with every bullet in cylinder
Kill 100 enemies with revolver
Kill 50 enemies
Destroy 10 destructibles
Spend $500
Collect all weapons
Collect and upgrade all weapons
Destroy 1000 destructibles
Blow 10 destructibles with one dynamite
Takeout 100 hats without killing enemies
Kill 1000 enemies
Kill 10 enemies with less then 1% of HP
Kill doctor boss
Kill fatty boss
Kill ratboy boss
Kill 100 enemy high in the air
Kill flying enemy with dynamite
Kill 3 enemies with one shotgun shot
Kill 100 enemies with dynamite
Kill 100 enemies with gatling
Kill 100 enemies with shotgun
Achieve x15 combo
Spend $10000
Complete 20 quests
Finish the wave with using a gatling gun and without overheating it
Upgrade weapon to max lvl
Make gun upgrade
Make 5 gun upgrades
Make 10 gun upgrades
Make 10 headshots in a row
Kill bitch boss
Kill all bosses