Easy way to unlock "Break out the Marshmallows & Not taking any Chances" Achievement.*(Burn up two Zombies at the same time with the Lighter & Burn up a Zombie)Step 1: Acquire the Sword Key. (Part of Story)
Step 2: Make your way to the first Save Room. (Mansion Map 1F East Side)
Step 3: On your way pick up the Lighter. (Room above Save Room)
Step 4: Avoid the two Zombies outside the Save Room. (One upstairs & one downstairs)
Step 5: Enter the Save Room and pick up the Fuel Canteen and fill it with Kerosene.
Step 6: Save your Game.
Step 7: Exit the Save Room and kill the first Zombie.
Step 8: Go upstairs and get the second Zombie to follow you downstairs.
Step 9: Kill him and make sure he drops on top or next to his buddy.
Step 10: Press
to access your inventory and press
on the Fuel Canteen.
This should unlock both Achievement HOPE IT HELPS