100% Achievements straight to the point.
Pup's Odyssey - Release the hot air balloon. Hard to miss, complete Potter's Rock level.
Donut County - Destroy the donut shop. Hard to miss, complete Donut Shop level.
The Flume Is Doomed - Destroy Raccoon Lagoon. Hard to miss, complete Raccoon Lagoon level.
Hacker - Hack into the mainframe. Hard to miss, throw the USB key at the security system outside Raccoon HQ.
Boss Fight - Win the boss fight. Hard to miss, complete the Boss Fight.
Redeemed - Bring everyone back from underground. Hard to miss, complete Catapult level.
Gamer - Stock up on gamer fuel. Pretty simple, buy the Energy Drinks from the Chicken Barn level cutscene, before buying the catapult upgrade.
Pyro - Set Pepper's trailer on fire. During Joshua Tree level, pick up a bonfire and move quickly under Pepper's trailer, setting it on fire.
Disrespecter - Destroy Trash King's monitor. During the Anthropology section of the Raccoon HQ, pick up a lit firework and make it explode on Trash Kings monitor.
Nerd - Complete the Trashopedia. First complete the game then go through your Trashopedia and read every entry for each item.
Pilot - Fly through the donut hole. Fly through the Donut Shop hole with your Quadcopter on the Aftermath level
Escape - Find Trash King's secret getaway vehicle. Again on the Aftermath level, follow the anchor above the clouds with your Quadcopter.
Quack Enthusiast - Quack 100 times. During any texting cutscene, press the Quack button 100 times.
Dethroner - Destroy Trash King's monument. After the boss fight, use the tornado to destroy the statue of Trash King.
Music Lover - Finish Gecko Park without collecting the radio. Pretty straight-forward, pick up everything on Gecko Park while making sure you leave the radio on the surface.
Egg Breaker - Break 3 dozen eggs. On the Chicken Barn level, destroy a dozen eggs. A tip for this is to activate the switch on the barn later in the level and let the barn shoot eggs on the ground.
Secret Soup - Make Chef's secret soup recipe. On the Cat Soup level, follow the secret recipe found in Chefs Recipe book, Soup + 2 shakes of salt + 3 shakes of pepper. When the soup gets orange, feed it to the bird.
Game Over - Lose the boss fight. Get killed during the boss fight.
Flawless - Complete the boss fight without taking damage. During the second part of the fight be sure to throw BK at the Kings Copter as fast as you can.
Bandit - Break into the vault at Raccoon HQ. During the Biology Lab section of the Raccoon HQ, use the commands on the wall to input the secret code found in the Bandit Note Trashopedia entry. [Up -> Left -> Down -> Left -> Grab] When the code is done, a cutscene will start confirming that the vault is now open. Now go inside the vault in the Security section of Raccoon HQ. If you are having problems with the code input, be sure to click each button once. Since the tentacle is wiggly it can happen that it pushes the buttons multiple times.