DIFFICULTY
Aside from 1 achievement, all of these achievements can be obtained on the normal difficulty. Enabling 'Friendly Lives' is fine but '99 Lives' WILL DISABLE achievements until you relaunch the game.

You will get these achievements from unlocking the characters:

Rescued Butternut Bro
You rescued Butternut Bro! Your gourd from another lord.

Resuced A Skeleton
You rescured A Skeleton! A bony vertebra buddy.

Rescued Ms. Witch
You rescued Ms. Witch! She has endless cats!

Rescued Grizzledude
You rescued Grizzledud. What is he doing here? Let's be friends.

Rescued Chainsaw Maniac
You rescued Chainsaw Maniac! Ready to cut loose!

Rescued Demon Joe
You Rescued Demon Joe! Like a bat out of hell.

*You can only unlock 1 character on each run. Once unlocked, they are replaced with a Free 1-Up

Pumpkin Man and Santa Pumpkin are unlocked by default.
Butternut Bro is found in Level 1: Forgotten Cemetery
A Skeleton is found in Level 2: Bloody Mansion
Grizzledude and Ms Witch are found in Level 3: Mystic Ruins
Chainsaw Maniac is found in Level 4: Spooky Church
Demon Joe is found in Level 5: Porphyry Palace

Here is a video guide for all characters and below are timestamps


00:00 Butternut Bro
00:36 A Skeleton
01:16 Grizzledude
02:19 Ms Witch
02:53 Chainsaw Maniac
03:38 Demon Joe

These achievements can only be obtained by certain characters

Win the game as Pumpkin Man
You won as Pumpkin Man! Get pumped!

Win the game as Butternut Bro
You won as Butternut Bro! Way to squash the opposition.

Win the game as A Skeleton
You won as A Skeleton! I knew you had it in you (I can see through your ridgaps).

Win the game as Ms. Witch
You won as Ms. Witch! Hope you had a feline time.

Crazy Cat Lady
Set loose 666 cats as Ms. Witch
ACHIEVEMENT NOTES
-This is a total of 666, so you can do multiple playthroughs and build up to it

Win the game as Grizzledude
You won the game as Grizzledude! He's got a good cranium, that one.

Win the game as Chainsaw Maniac
You won the game as Chainsaw Maniac! Got any plans for Summer vacation?

Win the game as Demon Joe
You won the game as Demon Joe! Now we have an all powerful demonic hero...wait a minute!

Mysteries of Abyxsis
Discover the five hidden mysteries of Abyxsis, the upcoming game by Imaginary Monsters!
ACHIEVEMENT NOTES
- Can only be done with Demon Joe
- There is 1 Flaming Scroll per Level
- They are always found in the very first stage of each Level

Below is a video guide for it, and below that are the timestamps


00:00 Forgotten Cemetery
00:15 Bloody Mansion
00:29 Mystic Ruins
00:43 Spooky Church
01:02 Porphyry Palace

Bulletproof Pumpkin
Beat a world without taking a hit.
ACHIEVEMENT NOTES
-This can only be done with Pumpkin Man

These are all story-related and can't be missed. Simply play through Halloween Forever using your own favorite character and on any mode. For a more detailed description of each boss, check out my guide for bosses

here

Completing the game will net you these achievements:

Beat Chainsaw Megamaniac
You bested Chainsaw Megamaniac! There's no chainsaw maniac tougher than this one.

Beat Big Bat
You bested Big Bat! Have you ever seen a bat so big?

Beat Green Hydra
You bested Green Hydra! Two heads are better than none, but that won't slow us down.

Beat Red Devil
You bested Red Devil. Yow, it's hot in here!

Beat Eyeskuller
You bested Eye Skuller! Eye spy with my little eye something that's about to explode!

Beat Necromancer
You bested Necromancer! Back to ghoul school with you, fool!

Beat Manleech
You bested Manleech! Say your lamprey-ers!

Beat Frog King
You bested Frog King! I toad you so!

Beat Blue Devil
You bested Blue Devil! Necessity is the moth of invention.

Beat Necroking
You bested Necroking! The return of Necromancer! How the mighty have fallen.

These achievements are specific to certain bosses

Chainsaw Dance
Make Chainsaw Megamaniac leave his chainsaw behind when he dies.


EXPLANATION
Proceed with the fight as normal and once he has 1 HP left, wait till he reaches the end of the level and rips his chainsaw. Once he has done this, finish him off and the chainsaw will infinitely keep bouncing back and forth.

Ozze It or Lose It
Watch Manleech vomit 10 times. Yucky!


EXPLANATION
This can be earned over multiple playthroughs. Every time Manleech reaches the end of the stage, he will vomit out 3 mini Manleeches. Just make Manleech do this 10 times and the achievement is yours.

Bad Touches
Get grabbed by Blue Devil three times.


EXPLANATION
This can only be done in 1 playthrough. Have Blue Devil grab and toss you 3 times. To get him to grab you, make sure you're above or far away from him, which will prompt him to jump. Now make contact with him in the air and he will grab you and throw you towards a wall of spikes. Do this 3 times to get the achievement. Make sure to have full health (And if you need to, he can summon butterflies which drop health upon death, so restock if you need to). And lastly, when he throws you, make sure to jump or else you will hit the wall of spikes

*These all stacks, so don't worry about doing them all in 1 game

Killed By Death
Destroy five hanging skeletons before they hit the ground.

ACHIEVEMENT NOTES
- You can only hit Hanging Skeletons. The ones from the Floating Coffins don't count
- Make sure to hit them in the air and not right before the ground
TIPS
- Go to A Skeleton's collectible area. There are no enemies and 4 Hanging Skeletons waiting for you



Spider Inciter
Knock five spiders off the wall.

ACHIEVEMENT NOTES
- These include both the Red and Blue spiders
- You don't have to kill em, just knock em off



Let Sleeping Frogs Lie
Wake up 6 sleepy frogs.

ACHIEVEMENT NOTES
- Can only be done during World 4: The Spooky Church
TIPS
- There are literally 5 in one room, so you can't miss this and will most likely accidentally get it



Crow No...
Run away from a crow for a long time.


ACHIEVEMENT NOTES
- You must let a crow chase you for 2 minutes
- You can have multiple crows chasing you, just make sure not to kill them
TIPS
- I recommend you do this right before the Chainsaw Megamaniac boss fight, as the area is small, has 2 Crows and can be easy to run around

These achievements don't have a specific category, so I'll put them here.

Secret Seeker
Destroy a breakable wall.

ACHIEVEMENT NOTES
- The area in World 2 doesn't count because it's part of the path. You have to find a breakable wall
- If you're going for the Rune Goon achievement, you will get this
TIPS
- At the first world, second room right before the exit, there is a breakable wall. Just hit it 3 times.


Rune Goon
Find all six hidden runes for a secret ending!

There are 2 Runes found in Levels 1, 2 and 3. Once collected, it will stay with you, even if you die and repeat the Level. Below is a video for all Rune locations.


ACHIEVEMENT NOTES
-You must do this in 1 whole sitting
-Can be done with any character

Bat Marm
Never harm little bats! Ever!


ACHIEVEMENT NOTES
-You can't hurt ANY bats at all (This includes Big Bat's bats)
-You can use any character
TIPS
-I recommend you use Pumpkin Man

Hardcore Gourd
Beat the game with 1 HP Mode enabled! HARDCORE!!!


ACHIEVEMENT NOTES
-You can use any character
-You are allowed to die
TIPS
-I recommend you play the game at least 10 times and get familiar with the level layouts, hidden character spots, event triggers and other important deadly hazards
- Make sure to collect all characters, then do it, so you can get a total of 9 Lives. Also take the Character Unlock routes (They are longer but are much safer)
-I recommend you use Butternut Bro

101 Spikes
Trigger spike traps 101 times.

ACHIEVEMENT NOTES
-This can be done through multiple Playthroughs
-This can only be achieved during Stage 3: Mystic Ruins
TIPS
-Just run back and forth across as many spikes as possible. I recommend you choose the area right before Ms. Witch's unlockable area (Make sure to clear out all enemies first)