NPC LIBERATOR - In Chapter 1, after you explore the rooftop a little bit, the path splits. Head north and you'll find a bonus area. Inside, you'll find an Energy Fragment and a Cloak. However, to get the Cloak, you'll need to fight a goblin. This guy isn't very hard, and you'll beat him quickly. After this, you unlock the achievement. In the rear of the room, you'll also find a ladder, leading to a Dragon Axe.

HAPPY CURATOR - In Chapter 2, you'll find various tentacles. Near the beginning, they're very difficult. However, after you locate the Rifle, and optionally, the Pipe, you can kill them quite easily. 3 of them are in the town, and 1 is in a secluded island located outside a shack (the entrance is underground in the Tunnels). Once you kill all 4, you'll unlock the achievement.

MOTHER'S SECRET - In Chapter 3, in the beginning area, head north. To your right, there's a Lava Mineral, and on your left, there's a Fire Stone and 500G. Then head into the small cave on your left. Inside here, you'll find a Reset Wand. There is a large amount of puzzles here that are fairly difficult to solve, so just follow these directions (I stole them from Arrpeegeez). For the first room:

For the left statue: Slide it north two spaces, then west to the wall, then north one more space and onto the button.
For the right statue: Slide it north one space, then west one space, then north three spaces, then east and onto the button.

For the second room:

Slide the first statue north two squares
Slide the statue on your left west and onto the button
Slide the next statue on your right north onto the topmost button
Slide the next statue on your right south one square
Slide the next statue on your right east onto the button
Slide the final statue north once, west once, and then south twice

For the third room:

Slide the first statue on the right north two spaces onto a button
Slide the statue on your left west onto a button
Slide the first statue you moved onto a button two buttons to the east
Slide the topmost statue south one square, onto a button, then push it another button to the east
Slide the southern-most statue north three squares
Slide the western-most statue off of its button two squares to the east and one to the south
Slide the northern-most statue two squares south and one west, onto the western button
Slide the last statue north and onto the last button

After this, you'll unlock another room. Inside, you'll find a Winter Horn, and if you interact with the sparkle, you'll unlock the achievement.

DEATH'S LITTLE HELPER - In Chapter 4, in the church, there's a northeast door. Take it. Inside, you'll find a Dark Bell, as well as the entrance to Death's bathhouse. Inside, speak to Death. He'll give you Mint, Ginseng, Liquorice, and Green Tea. Head up. In the big maze, deposit the Ginseng in the northwest, Liquorice in the northeast, Green Tea in the southeast, and Mint in the southwest. After doing this, speak to Death again. He'll give you 4 Empty Bottles. Fill them up at the pools and speak to Death once again. You'll enter a boss battle of sorts. Your goal is to fully heal Death by giving him items. When he complains about work or seems angry, use Green Tea, if he complains about his weight or weeps, use Liquorice, if he coughs, use Mint, and if he's lacking in energy or sleepy, use Ginseng. After you finish the battle, he gives you Herbal Tea, and the achievement unlocks.

WITCH'S NIGHTMARE - In the escape sequence in Chapter 5, when you talk to Harold, he mentions a witch. Walk up and talk to the witch attacking someone. You'll then enter a fight with Kalabhii. She's super easy. Just beat her up and you'll unlock the achievement.

THE IRON GIANT - In Chapter 3, to the far west of the starting area, you'll find a cave. This leads to the Tunnel. To the far west of that, you'll find the Entrance Tunnel. In the top, you'll find a locked door. The code is 1813211. Inside, you'll find 3 Runic Potions and 5 Fire Stones, as well as a secret boss. He will demolish you for quite a while, so I'd recommend using Hero Calls. Only refrain if you've unlocked Square Tiles. After killing him, the achievement will unlock, and you'll find Safe Tea Boots.

STARING CONTEST - In Chapter 5, in the same area you fought Kalabhii, you'll find a cell with three prisoners. Sit in front of the door and stare at the center one for a while to unlock the achievement.

MASTER MAPPER - After you gain 725 points, you'll unlock map edits. You'll find various mapping errors throughout the game you can find items in if you use the map edit next to them. Here's where they are:

Chapter 1 - Northwest corner of the interior of Evil Castle just after fighting the optional Orc battle. Room contains a Chainsaw and 800G
Chapter 2 - Just west of the Hidden Cottage at the end of the chapter. Hole contains a Basilisk, 3 Herbal Dusts, and 3 Jewelweeds
Chapter 4 - In the eastern hallway of the Church, connecting to the bathhouse. Door contains a battle with a Ghost, two Spirits, two Angry Spirits, and two Gloomy Ghost; they’re guarding a chest that contains Devil Grapes
Chapter 5 - In the Princess's Tower, if you climb back up after going through the window and descending the vines on the wall. The chest in the door contains an Uber Hammer, and will extend the time limit for escaping by five minutes