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