Here is the full list of all 34 Safety First! achievements.
Commit suicide for the first time
Beat 20 levels of Classic campaign
Win the totally unfair Trampoline 2 level
Retry a level 10 times in a row
Use a gamepad so you actually have a chance at this game
Beat Garbage Compactor without using up all your Magical Yellow Repair Liquid
Loose a limb shortly after winning
Beat all levels of Classic campaign
Beat all levels of Advanced campaign
Beat 20 levels of Advanced campaign
Beat all levels of Space campaign
Beat 3 levels of Space campaign
Beat 50 levels
Beat 30 levels in PEP mode
Beat 30 levels in DRNK mode
Beat all levels of Classic campaign in DRNK mode
Beat all levels of Advanced campaign in DRNK mode
Beat all levels of Space campaign in DRNK mode
Beat all levels of all campaigns in DRNK mode
Beat all levels of all campaigns
Beat all levels of Classic campaign in PEP mode
Beat all levels of Advanced campaign in PEP mode
Beat all levels of Space campaign in PEP mode
Beat all levels of all campaigns in PEP mode
Beat all levels of all campaigns in all modes
Endure the full credits soundtrack
Commit suicide 23 times
Skip a level for the first time
Beat a level that you skipped before
Beat your own best time
Beat your own best time 30 times
Beat Tutorial 2 without using up all your Magical Yellow Repair Liquid
Be idle in a level for 2 minutes
Tamper with the savegame