N.O.V.A.: Near Orbit Vanguard Alliance HD

With Earth no longer able to sustain life, huge artificial satellites called "near-orbitals" were constructed for people to live on. To protect themselves, the near-orbitals banded together to form N.O.V.A., the Near Orbit Vanguard Alliance. Now, a strange threat has emerged from the darkness of space. A Marine ship, reported missing just a week ago, has suddenly reappeared and is headed directly for the near-orbitals, ignoring all communications. Against his will, retired Marine hero Kal Wardin is forcefully returned to active duty to prevent mankind's annihilation.