This game is easy.
The person above you will end their post with a wish. It could be anything from 'I wish I had a taco right now' to 'I wish that my loved one wasn't in another country' to 'I wish that everyone in the world got along'.
You will then ruin their wish. Respective examples: 'You got a taco, but it was filled with cardboard and cyanide instead of meat and cheese.' 'Your loved one returned home but s/he doesn't like you any more.' 'Everyone in the world gets along just fine, but then aliens invaded and now we have intergalactic wars that are worse than any wars on just Earth ever were.'
Then, after you ruin the person's wish, you make your own to be ruined.
If the person above you failed to make a wish from forgetfulness, or whatever, keep the game going by just making a wish.
I, of course, will begin.
I really wish I had some vacation time from work.
Your boss doesn't like you :/
I wanted to go to London :3
You got on the plane to go to London, but the plane had to turn around and go back to wherever you lived because London broke off and floated across the ocean.
I wish I could fly. :3
You can fly but the weather becomes so bad, it's too dangerous to go outside. Permanently.
I wish I didn't have any enemies.
You don't, because you are stuck on an island with no humans to be enemies with.
I wish I was not so nostalgic.

- Okay, you're not nostalgic, but you already live in the past. :D OHOHO TROLL LOGIC!
...I wish I weren't such a troll. ono
Granted, but you bore yourself to death now. D:
I wish it would be SUNNY in the freaking SUNSHINE STATE.

- Granted, you're now crispy like a rice chip.
I wish I'd stop coughing.
Granted but you can't speak and therefore can't wish for your wishes.
I wish for a smoothie.

- Granted, human smoothie with hair as a topping!
I wish I had Guy-Manuel's helmet. ono
Granted but you can't get it off your head and you suffocate. D:
I wish I felt better.

- Granted, but now you can't relate to people that feel bad.
I wish these cough drops weren't square shaped....who makes square-shaped cough drops?
Granted, now they are rectangular.
I wish it wasn't raining so I could walk.

- Granted, its icy out now.
I wish my nose weren't plugged.
Granted, but you are locked in a porta-potty and have to breathe through your nose and smell the scent of rotting crap.
I wish I knew how to cute up a honey dew.

- ....wow, you're mean. XDDDD
Granted but it rots immediately.
I wish I could sleep right now.