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