Here is the full list of all 20 The Adventures of Sullivan achievements.
Kill 50 enemies in a row without dying or quitting.
Kill 100 enemies in a row without dying or quitting.
Kill 250 enemies in a row without dying or quitting.
Kill 500 enemies in a row without dying or quitting.
Get to the cantina.
Open your first supply crate.
Eat a hamburger.
Die for the first time.
Fall into a trap.
Defeat the desert boss.
Defeat the jungle boss.
Defeat the cave boss.
Defeat the snow boss.
Defeat the city boss.
Defeat the final boss.
Complete the first level.
Crash-land your ship.
Use a health recharge station.
Rescue C.A.T.
Ride an elevator.