find skulls and get achievements
After Halo 3 there was halo wars, halo 3 ODST, and Halo reach. A new company (not Bungie) will be making a Halo 4 and rumor has it there will be a remake of Halo Combat Evolved.
get a new halo 3 disc
No, It does not. Halo ODST is the story of a squad in New Mombasa before/during the events of Halo 3
Halo Games in Order of Release (oldest to newest) Halo : Combat Evolved Halo 2 Halo 3 Halo Wars Halo 3 : ODST Halo : Reach
There is HALO 3 O.D.S.T (recon) and a new game called halo reach.
No. It is a new vehicle brought only to Halo 3.
If you count Halo 3: Recon, but you don't play as the master chief on that.
Well, it is an entirely new game, so proably not. But the game will come with halo 3...
Well You should either get another new copy of halo 3, or clean your console.
Yes, halo 3 mythic is the exact same thing as halo 3 just doesn't have the campaign, also Halo 3 mythic has the new mythic maps included. Online will not change during any gameplay.
There is halo 3 ODST but bungie has stopped making new halos. Halo reach takes place before combat evolved.
there will be new vidmasters for odst, but halo 3's vidmasters will remain the same.