Here is the full list of all 18 Super Forklift 3000 achievements.
Score 35k on Stage 1
Score 85k on Stage 2
Score 90k on Stage 3
Score 130k on Stage 4
Score 375k in All Stages Mode
Complete Stage 1 without dying
Complete Stage 2 without dying
Complete Stage 3 without dying
Complete Stage 4 without dying
Complete All Stages Mode without dying
Eliminate the first boss
Eliminate the second boss
Eliminate the third boss
Eliminate the fourth boss
Defeat any boss in 40 seconds or less
Defeat 500 Angry Rocks
Defeat 15 enemies in an explosion
Destroy 50 enemy shields