Here is the full list of all 24 Pixel Boy and the Ever Expanding Dungeon achievements.
Die 100 times
Complete Act 4 up to the first boss
Complete all Acts
Defeat the Final Boss
Defeat all four bosses in the game.
Open 100 treasure chests
Pickup a total of 100 keys
Defeat Penta Vultis
Try every power up in the game
Obtain 10,000 coins
Use Pixel Boys computer to check out a super awesome game.
Complete Act 3 up to the first boss
Use each one time use power up at least once
Hold 15 keys at a single time.
Spend over 500 coins on power ups
Complete Act 2 up to the first boss
Defeat Frank Indadark
Obtain 150 Coins
Enter the Dungeon and receive your Pixel Powers
Open 10 treasure chests
Complete Act 1 up to the first boss
Defeat Moby Richard
Obtain 1500 coins
Complete the Tutorial