Here is the full list of all 33 The American Dream achievements.
(Chapter 9) Defeat the hose without getting hit by any bolts
(Chapter 15) Shoot 15 beer cans into the trash can
Make a milkshake
(Chapter 5) Change your mind about which one of the twins you like
Experienced the fake ending
(Chapter 22) Witness the dawn of the Second American Revolution
(Chapter 21) Blow up 20 cars
Shoot half the hidden stars
(Chapter 19) Shoot a fish in mid-air
(Chapter 17) Eat the entire stack of waffles
Buy 50 Guns
(Chapter 18) Keep checking records even after given the option to Give Up
(Chapter 16) Ensure all daisies survive til the end of the stage
(Chapter 12) Hit yourself in the head with toilet paper
Reach Intermission
Pump the shotgun 10 times without shooting
(Chapter 11) Learn how babies are made
Eat 30 pieces of food
Manually eject and reload your gun 100 times
Shoot 1000 bullets
(Chapter 8) Out-dance Rex George
(Chapter 7) Earn at least $5.00
(Chapter 4) Catch the fast ball with your face
Shoot 1 hidden star
(Chapter 1) Begin your journey into The American Dream
(Chapter 3) Shoot the down the ducks with 100% accuracy
(Chapter 6) Shoot down 5 pins from the back row in the shooting game
(Chapter 10) Eat all of the maggots from the cheese
(Chapter 13) Listen to all of Rex's objection before shooting him
(Chapter 14) Complete the stage without letting a single rat dough through
(Chapter 20) Complete the stage without a single civilian casualty
Experienced the true ending
Shoot all 48 hidden stars