If you happen to know the story of The Monkey's Paw, you probably have a general idea what this game entails from the creative level. Be careful what you wish for, so to say. This is a rather common forum game, but there is still much fun to be had in ruining the most simple of wishes. A very basic example:

I wish real life had a save feature!

This is a quite innocent wish with lovely possibilities, but the next poster would do their best to "ruin" the wish. Such as:

Granted, but we run off of a single save file, with auto-save turned on.

Let's get things started!

I wish we had more info on the 9th horizon.

Spring comes, but Hiver still isn't born. Sorry.

I wish for a ghost horizon.

Low blow Ghostie :C

You get a Ghost Horizon, but it's actually an electropop album by some band named Göst.

I wish Hiver had worn an undershirt in the AssHora rendition of NoroPierre.
Fix that, someone.

Your wish is granted, but the edits are made to copies yet to be sold, thus nullifying it in regards to your own copy.

I wish that we knew the result of Elef's confrontation with Moira.

We get to know the result, but only to find out the master mind behind everything is the Silent Hill 2 dog.

I wish that we get Revival tour dvd.