Missions.
No, Halo Reach shows what happened before Halo 1. In fact, in one of the missions in halo reach, you can see Master chief
if you mean co-op then yes you can
No you can't create your own missions. The closest thing to that is Forge.
it will last until halo reach the game comes out from September to December
It's a little bit longer than halo 3
It doesn't take long it downloaded for me in a few minutes.
Its over
Halo reach is older
no, Masterchief is not in Halo: Reach. Halo: Reach is set before the discovery of Halo, if you have or Know about the Halo book: The Fall of Reach, it is a closer view of the plant reach. but there are some other Spartans in it!
There are no skulls in Halo Reach.
halo reach is the bomb