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