Twists

The link was not specific about the type of game - big shoot up, RPG, tactical or what?

It''s not a very easy storyline to twist. Something about the origins of the disease would be the obvious choice...

Superpig
- saving pigs from untimely fates
- sleeps in a ham-mock at www.thebinaryrefinery.cjb.net

gaussuk,
its a FPS
Tricky

How about this.
The aliens are invincible - the end of humanity?
But then your hero gets a mysterious contact from some being from a higher dimension. S/he has been watching the progress of this evil alien empire as it has spread across the universe - now the time has come for it to be stopped!
Your hero has been chosen to do the stopping.
He has to fight or by stealth or what ever get into the heart of the evil aliens central city - via many levels of planets, spaceships, hunts for special weapon, computer hacking, maybe a babe or two ( how about he meets some beautiful girl on a planet enslaved by the aliens )or what ever.
(If you use the idea you can give me a credit.)

How about this.
The aliens are invincible - the end of humanity?
The disease is used by the aliens to exterminate natives of the planets the conquer.
Your hero has to fight or use stealth or what ever to get into the heart of the evil aliens central city - via many levels of planets, spaceships, hunts for special weapon, computer hacking, or what ever.
On the way he meets others from planets destoyed or enslaved by this evil empire.
He gets to the central city and has to find a cure for the disease before it wipes out all of humanity and then finaly he destroys the heart of the alien''s empire.

Sorry for 2 posts. In the first one I forgot about the disease so reposted.

The story is a little cleche (most are) but has potential to be very deep. If you''re going for international intrigue, and I think you are because of the prospect of the Earth''s destruction, then consider this scenario:

Your character is from the Red Hand Army.

The Army''s experimental weapons seem to be the only one''s capable of harming the aliens. For this reason the US government sendws you in to stop the threat in New York.

The twist could come later as the disease is released. The virus, obviously created by the aliens, kills all it touches, exept you. You wonder about this and question your loyalty to Red Hand.

It turns out Red Hand has been influenced by the aliens from the start. This explains the effectivness of their weapons and your resulting immunity. The fight turns to your former base of operations as you battle people who were once your friends, but now compromised by the alien threat.

The climax could come as you duke it out with your mentor and discover the nature of the virus. The virus is actually spread by members of Red Hand who have been carriers from birth. A sad end comes when the antivirus is released and it winds up killing your character because he was compromised by the aliens even though he was the one who is credited with stopping them.

Just some thoughts from,
Just 3D

thanks everyone who has posted there ideas, i will credit those who helped if i end up using those ideas.
Tricky

Here are some of my ideas:

1) Some of the aliens, tired of death and destruction, betray their race and fight with the humans. The aliens show the humans how to create armor and weapons capable of battling the aliens. They do all of this in secret so the invading aliens are caught by surprise. The US Government then starts creating their brand of alien killers.

2) The battle for Earth turns disasterous. The humans simply cannot defeat the aliens and their technology. The US Government gathers about 500 of the world''s most important people and hides them in a secret mountain base (A la Deep Impact). There they hope to wait out the invasion.

3) The antidote for the disease is found to be deadly to the aliens, and so the humans begin splicing viral properties of viruses with the antidote to create a "disease" of their own that''ll cure the humans and kill the aliens.