HALO is one FPS that really did introduce many new gameplay elements. It offers all that is said below and the modifications already in development look to refine and improve the "HALO experience" even more!
You have recently crashed on Halo, and discover that there are Spartans in the area. You are to find and rescue them. Replaces a30 (The Maw) for Halo: Combat Evolved. Make sure you backup before you install.