OK, this is your 'getting used to moving' as well as a really challenging level in general. You start out calibrating (i.e. learning movement) in your suit and then go through the green doors. Head right, you'll be stuck immediately, Then head left and follow the guys. They'll lead you right to the bridge.

You get to chat with the captain, and he gives you a gun. Now head left and then right to get to the cafeteria area, where there's a right going on. Help them out. Go out to the gas corridor. You hear the 'hit us' and then go around forward to the air lock. Fight here, and go in for the shield inside it.Come back out.

Now go down past the guards. You have to duck-and-jump to get over the barriers there. Go around the shield and the "32" area with more shields. Duck under and keep going.

You hit the landing now. Go around, then past the window where you overlook the pods being shot out. Go into the tunnel area and then into the Cryo Bay. Now go into the tunnel with even more guys. Now you jump into the lifeboat, and you watch a video of your group going down to the ring.

Master Halo Walkthrough