Here is the full list of all 29 Mega City Police achievements.
Gather $1,000,000
Kill 5 enemies with a car's explosion
Beat the game under 15 minutes in classic mode
Beat the game on extreme difficulty in classic mode
Beat the game on hard difficulty in classic mode
Unlock 10 skins
Cause 50 enemies to die by fire
Decapitate 50 enemies
Kill 50 enemies by throwing a melee weapon
Kill 100 bosses
Beat the game on normal difficulty in classic mode
Irradiate 100 enemies to death
Blast 100 enemies into pieces
Pulverize 100 enemies into a mist
Kill 1000 enemies
Electrocute 100 enemies to death
Impale 100 enemies to death
Find 10 collectables
Clear the Mega-Corp level
Beat the final boss without taking damage
Clear the Japantown level
Clear the Ruins level
Get killed
Clear the Contruction Site level
Clear the Suburbs level
Complete the tutorial