Here is the full list of all 60 Monster Bash HD achievements.
Complete Episode 3
Complete all episodes
Defeat Nemessis in all 3 episodes.
Kill 50 Spiders
Complete Episode 2
Kill Igor without killing any of his flies
Get petrified 5 times
Save 4 pets with 1 one shot
Score splatter bonus on 50 skulls
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Complete Episode 1
Beat par time on any level.
Smash 10 zombie heads before they hit the ground.
Finish an entire level without taking any damage
Break 100 objects
Water a plant
Read every page of the instructions book in the menu
Get all bonuses on any level
Finish E1L06 without getting hurt
Destroy 50 treasure chests
Finish any non-boss level in 1 minute or less
Crawl over 100 tiles
Get 100 Check points
Shoot 10000 rocks from slingshot
Get 5 heart pickups while having full health.
Collect all the Johnnies in the game
Collect 1000 candies
Destroy all Skull Watchers in the game
Break all treasure chests in the game
Beat all par times in the game
Collect all bonus pickups in the game
Collect 500 Candy Kisses
Collect 250 peppermints
Complete E1L02 without disturbing the hanged skeletons
Solve a puzzle requiring the use of blocks
Get 8x splatter bonus on Skull Watcher.
Extinguish the candle with fireball
Ride 50 brooms
Create and post user level
Die 50 Times
Kill 50 enemies with the Rocket
Kill 100 Zombies
Kill 50 Thing Hands
Kill 50 eyeballs
Kill 50 Witches
Kill 25 Pumpkin Heads
Beat Cyclope without getting thrown in the air
Beat Count Chuck...fast
Kill enemy with pushable object
Race Frank Lloyd Rat to the other side of E1L01 and win.
Finish any episode on Hard difficulty
Finish any episode on Nightmare difficulty
Save 100 pets
Finish the entire game with 100% on every level
Find all the secrets
Complete all achievements