Well...this is fic material right here :P
I honestly think that my characters--who are all connected, actually--would form an alliance to end the thing. But they'd still die.
Cam would die first, because she would step off the pedestal too soon and go boom. (She's a vampire now and being such a creature goes against everything she is so much she'd seize the opportunity to put herself out of her misery.)
Jamie, Tori, and Andrew would be in charge of getting the donation-thingies.
Andrew would probably die second, though probably by animal.
Justin, since he is a freaking child, would take Andrew's place on the donation squad.
Sarah would be in charge of food, plant-wise and preparation-wise, but Nora would be in charge of getting meat. (Because Sarah would know the do's and do not's of plants from her CIA days, and Nora is the only one out of everyone else--eh, except Tori--who could consistently catch/kill critters.)
Both Sarah and Nora--who knew eachother when they both lived in the US--would both be overprotective of Justin, so when the game-masters unleash some horror trap and Justin gets caught in it, Sarah saves him...but ends up getting caught in the trap herself and dying. Tori would try to take care of Justin's injuries but they would get infected anyway--but luckily Nora goes badass-mother on whoever might be watching and gets some antibiotic. Justin would later die from accidentally ingesting a poison berry.
At this point Casper, who has been scheming with Kasey about how to potentially disable to invisible dome around them, would be rather incapacitated from all the useless death. She would find herself unable to eat and drink and speak and would basically become an empty shell, and eventually die of dehydration.
Haru would be mauled beyond saving after trying to calm down the pack of rabid wolves sent after them--something not even Max, being a wolf animagus, is dumb enough to try.
Kasey, Jamie, Tori, Nora, and Max would give up on trying to have roles and just start trying to escape.
Kasey would fill them all in on what she and Casper discussed/discovered--but before she can finish a game-lover from the outside would send a donation in the form of a bullet to Kasey's head.
Tori, while sad, would be amazing unaffected by all the death. Nora would only cry when she thinks no one can see her. Jamie would still be trying to keep everyone's spirits up, but even she is ready to give up. Max, who by now is ready to murder everyone in charge of this pile of shit, would be extremely testy and unable to speak to anyone in any sort of calm fashion. She would regularly tell Jamie to shut the fuck up every time she makes a joke.
After much discussion the group would think they have a way to disable the dome, but Max is very much against actually trying it because the person who sets off the reaction will most likely die and they really don't need to lose anyone else.
In the middle of the night, while on her watch, Tori would gather the thing(s) they'd made that would supposedly disable the dome and travel to the edge to set it up. Max, sensing something is off, would wake up and notice Tori gone. She would shift into wolf form and track Tori, but not reach her in tome to stop her from setting off the device. It would cause a huge electrical explosion, frying Tori and blowing Max back. The dome would still be there, except now it is completely visible.
At this point Max would be a mofucking mess, which would play to their benefit as the mutant animal attacks increase. Jamie would end up with a broken nose as a result of making a weak pun within earshot of Max. Jamie would try using some of the healing paste they got at the beginning to see if it helps her nose, but it has been left un-cooled for too long and is now extremely toxic. The close proximity to her eyes, nose, and mouth would cause the fumes to burn her lungs and eyes, and the paste itself would act as an acid and eat its way to her brain before Nora and Max can get it off. They would both suffer acid burns to their hands.
Nora and Max would survive several more days and manage to make it back to the starting point. Two winners are not allowed and they know they can't survive long enough to physically dismantle the dome. Nora would pick up the last weapon--a dagger--and twirl it thoughtfully. After a few moments she would press it to her neck and tell Max to do her best to end the games. Max would quickly wrest the dagger from her, slap her, and step out of her reach. She would tell Nora to live on and be a mother and a lawyer or whatever the hell she wants to be, to leave all this in the past and just survive. Max, now having lost everyone important to her, would have no reason to live and would not hesitate to cut her throat. She would, however, turn away from Nora so she wouldn't have to see another person killed.
Nora, after making it through the interrogation post-games, would take her winnings and take her family and travel to another country, where she would live on and be a mother and a lawyer and work in secret to take down the regime of her homeland. Eventually she would become too old to continue, and her daughter would willingly take up the reins. Nora would be sure her mission would not be completed in her lifetime, but on her deathbed her daughter comes to her with news of their success. She would swear she could see the smiling faces of those that died in her game, and she would die of natural causes with a smile on her face.