While you cannot die in this dmod, some people have reported being stuck near the endgame, so I thought I'd write a walkthrough for AHP.
Outside the Haunted House
You start near a boat. Go two screens left and two screens up. When you're ready, enter the house through the left door; you cannot enter through the right door (before you enter, you may want to wander around, but there's not much to do. You can find a few graves and look at them, but that's about it).
Inside the Haunted House
Really weird things will happen in this house. Just ignore them, nothing in this dmod can hurt you. Go one screen north, one screen west, and one screen south. Go upstairs and go one screen east, one screen south (the zombies in this room will rise when you step on them, you can hit them if you wish), and one screen west. Go downstairs. Save your game if you feel like it, then go one screen east. Watch the cutscene.
Push the ctrl key on your keyboard to scare people when they're close enough to the coffin. You'll probably fail at first, because you won't know exactly what 'close enough' means; also because the last persons you must scare are very fast, but it gets easy with practice. If you fail, Bob (the one who wants you to scare people) just tells you to try again. When you manage to scare ten people, Bob tells you to take a break.
Inside the Haunted House, again
Just speak with Bob, and you'll find yourself in the haunted forest.
Bob tells you to hide in the trees to scare people, but it is actually impossible to scare anyone at this point, so you'll just have to kill everyone you meet (you can't kill Bob until you've killed everyone else). Go one screen south. Keep hitting the girl until she dies. Go one screen west. Kill the old person there. Go one screen east, then one screen south. Kill the woman. Go one screen east. Kill the man. Go one screen north. Kill the girl. Go one screen south and two screens west. Kill the man. Go one screen south and one screen east. Kill the girl, then the man (you can't kill the man until you've killed the girl). Go one screen east. There should be a girl here (she doesn't appear until you've killed everyone else except Bob). Unfortunately, she's out of reach. Open your inventory (enter key on the keyboard) and equip the magical 'Graham Cracker' item. Keep throwing Graham Crackers at her (shift key on the keyboard) until she dies. When she's dead, Joshriot will tell you to kill Bob. Go back to the screen where Bob is. You must kill him, but he's immune to your attacks; so hit the pole behind him instead, and watch the short ending.