First, see here for the history of the cornfield, which involves telekinesis, a short story by Jerome Bixby, Rod Serling, Bill Mumy, and Second Life griefers.
The cornfield is back in Second Life as a demo of the new (actually, still in Beta) Experience Keys.
In Second Life we must all grant permission every time an object wants to interact with us. For instance, there's a puddle of oil at our Robot Sanatorium. Oil is slippery, right? When an avatar walks across the puddle, she slips and falls-- but only if she clicks yes to the blue menu box that pops up. Now matter how many times it happens, she must respond every time. Sweetie likes the example of a pickpocket on a Victorian sim: "Malefactor Resident would like to pick your pocket. Please type [Y] or [N]."
The Lindens are releasing what they call Experience Keys, which will require only a single granting of permission in certain situations; after that, permission will be granted automatically. That means that every time an avatar walks across the oil puddle at the robot sanatorium, it would slip and fall.
Here's the Linden's announcement about avatar keys, and Torley Linden's video on the subject:
Experience Keys, which will be available to selective creators, will allow an experience to attach and detach HUDs and worn objects and teleport you without the need for dialog boxes.
The Cornfield is a game that uses this experience key system. You are teleported whenever you come into contact with a glowing green doorway or are "killed," and objects attach and detach as required for game play.
The setting is a farm. There's a barn...
... with corn cribs..
.. and there are ears of corn scattered here and there throughout the region.
Your task is to fill the basket that will attach to your back with corn and deposit in the corn bins, where you will be given one cornbuck for every ear.
Unforutnately, there are spooks to chase you and "kill" you.
Their behavior is semi-intelligent. If you get within about five meters of you they sense you and begin moving toward you. They also call their peers, who rez nearby and come after you as well.
Here I am standing stupidly still while surrounded by at least a half-dozen the creatures.
When they get you, you are spawned in this cemetery...
When you first arrive, you are armed with a plank...
As you earn cornbucks you can purchase what appear to be better weapons-- a chainsaw...
... a grey goo grenade...
... or a shotgun...
Alas, the chainsaw and shotgun aren't any more effective than the plank. The grenade is omnidirection (meaning you can get the monsters behind you without stopping and turning , but cannot be re-thrown until a few seconds have passed.
Assorted structures provide temporary hiding places, which get the critters off your trail...
... and sometimes a health regenerating machine appears at a random spot on the sim.
Before arming yourself with ineffective weapons, it's best to buy all four armor power-ups.
It takes quite a few runs through the cornfield to buy anything at all.
Your best bet is to keep moving. Running like hell will get you more corn and minimize your "deaths."
It's an addicting game, much better than it would have been if the monsters had to have your permission every time they teleported you. You can try it from LR Portal Park. Just look for the passageway to The Cornfield.