"They came to our planet, and took over it. This simply. Now, half a century later, they have made that planet theirs. The plants have started changing. Alien animals start conquering our fauna. Even the day and night cycle has changed, accomodating to their tastes. And the worst part? We are getting used to it. The more a day passes, the more we feel those changes like normal. Slowly, steadily, we're becoming one of them.
But we're not letting that happen. We know our origin, we know our heritage. No matter how much they're trying to transform us, we'll persist. No matter how hard they're trying to neutralise us, we'll persist. No matter how much they're trying to show we're invaders on our own world, we'll persist! From this day on, we're showing some alien bastards who was born here."
The Leader of the Rebellion's Diary, on the day the Federation started.

Year 2034, a meteorite made of an unknown material landed on a roadside in Athens, Greece, causing 3 casualties and 50 injuries. After research, it was found out that the meteorite was made of an alien radioactive material with around 30 isotopes and an atomic number of 134. It would normally be just a high-energy uranium, were it not for its weird strong nuclear forces: while its free neutrons would normally cause fission on contact with other nuclei, it also had a chance to just stay put in it, reversing the radioactive decay. Also, the electrons were so free, they would easily and abnormaly jump from atom to atom, constantly changing its charge, and even being able to colliding with nuclei (either causing fission, or even sticking to them temporaly) As a result, the material constantly changes the type of energy it holds, from electricity to thermal energy, to light energy, to radiation, to kinetic energy, to every one. This made it a perfect battery and energy transformer.
6 months later, it was found that the material was really easy to be artificially made in a more stable version but less powerful, giving food for thought in the theory that someone had already done so.
Some years later, after engine technology had advanced to unmeasurable counts thanks to the new material (called Elementum, because it gave humanity the power of elements -literaly), they sent off in a quest to find the origins of the meteorite. They finally found a planet with many natural deposits of Elementum. However, at landing, eager they were to find that the place was actually inhabited by alien species. The colonists sent on the harvest for Elementum started attacking the alien colonies in a battle for the deposits, which ultimately resulted in their slow and painful death. Afterwards, the aliens sent all of their forces (an unbelievable amount) towards Earth.
No matter the humans' newly advanced technology that could easily compare with the aliens', their intense will and their cunning tactics, they only managed to hold off for so long before they were outgunned and outnumbered, with internal conflicts not helping at all. When a desperate attempt to launch a sneak attack with mass destruction weapons to cripple or even outright destroy the aliens' homeplanet failed miserably, it was obvious to everyone that the battle was ultimately lost. And so it was.
Now, the aliens have taken over the planet, chasing down the last survivors of Earth. For 2 generations, the aliens prospered, while the humans struggled to survive, especially because of the changed conditions and fauna artificially brought to Earth by the aliens. However, the flame of liberty has not yet been extinguished. The remaining human colonies have started attacking the aliens in stealth attacks, stealing back their technological achievements, spying on their actions, and generally slowly but steadily gaining influence over the earthly grounds. Human, an invader on his own planet, is ready to show the former outsiders who belongs to this planet.

That's where you come in. You are human rebellions, trying their best best to not only survive, but also secretly help in outrunning the aliens. Becoming members of the Federation -have you been able to survive enough- you will become a member of the steady liberation of Earth.
Each of you will start off as a human in a place of your choosing. You can be a lone wolf, an escaping prisoner, or a member of a small, independent team of NPCs or other players -as long as it is logical and not game-breaking, your choosing.
I will be the Head of the Liberation, a mysterious fiqure known to almost everyone solely as the Tip of the Spear. Being the Game Master, I will have a force of NPCs that will have already acquired some technology, but will be unable to win the battle -even though they steadily get an advantage- without your help.
So, here's your application template:

Name
Nationality
Current Place
History
Characteristics
Speciality (in terms of abilities)
Equipment

So, ready, set, go!