Here is the full list of all 30 My Friend Pedro achievements.
Kill 2000 enemies
Kick enemies 100 times
Get a 50x combo
Kick a Gas Canister in to the face of an enemy
Stick a knife in to an enemy
Juggle basketball 10 times without it touching anything
Complete a level without firing a weapon
Finish the game
Finish chapter "The Internet"
Finish chapter "The Sewer"
Kill at least 3 enemies with one explosion
Kill 1000 enemies
Dodge 1000 bullets
Kick a frying pan in to the face of an enemy
Kill enemy by ricocheting bullet off frying pan
Finish chapter "Pedro's World"
Finish chapter "District Null"
Break 100 crates
Jump through 10 windows
Kick a skateboard in to the face of an enemy
Kill 500 enemies
Get an S-rating
Finish chapter "Old Town"
Get a 20x combo
Flip 10 tables
Kill an enemy using a barrel
Get a 10x combo
Get S-rating on 10 levels
Get S-rating on 25 levels
Get S-rating on all levels