Here is the full list of all 22 Pressure achievements.
First checkpoint not accessed
Passed on primary weapon
Collected all coins
Never Died
Got best rating in all levels
Defeated Wellness-Train
Got best buggy upgrade
Defeated Metal Count
Helped out a friend
Played game in co-op mode
Defeated Mantis
Fell off a bridge ten times
Defeated 1000 enemies
Played 'Easy' Mode
Played the 'normal' way
Played 'Absurd' Mode
Barely finished with pressure…
Defeated 6 enemies with one strike
Destroyed 8 enemies with one strike
Destroyed all enemies
Defeated an airship
Defeated 4 enemies with one strike