Here is the full list of all 19 Angry Video Game Nerd Adventures achievements.
Enter a cheat code
Kill Naggi
Beat the game on "Normal" or higher
Beat the game over Halloween weekend on Normal or Higher difficulty
Drink 100 beers
Die 100 times
Ride the Fire shark
Kill Santa
Die 1000 times
Collect 200 1ups
Find all S*** Pickles
Find all the cameos
Find Craig
Find all playable characters
Beat the game on "Old School" or higher
Beat the game on "Hard as Balls" or higher
Beat the game on "Impossible" or higher
Beat the game on "YOLO"
Found Matthew Lentz