Here is the full list of all 8 Dude Cops achievements. It takes around 0-1 hour to unlock all of the achievements.
Save the cat from the tree
Rescue the lost ball
Remove the pesky mouse
Help the Old Lady across the "street"
Teach Lil' Timmy a valuable lesson
Have a pleasant chat with a zombie
Examine the barrel
Does Dracula wear boxers or briefs?