Complete the following missions within the allotted time. This can be done playing under the easy difficulty setting without activating any Skull Modifiers, and skipping through unnecessary engagements.

Halo 1
Pillar of Autumn: 15:00 minutes
Halo: 20:00 minutes
Truth and Reconciliation: 20:00 minutes
Silent Cartographer: 15:00 minutes
Assault on the Control Room: 15:00 minutes
343 Guilty Spark: 15:00 minutes
The Library: 25:00 minutes
Two Betrayals: 20:00 minutes
Keyes: 15:00 minutes
The Maw: 15:00 minutes

Halo 2
Cairo Station: 15:00 minutes
Outskirts: 15:00 minutes
Metropolis: 15:00 minutes
The Arbiter: 15:00 minutes
The Oracle: 25:00 minutes
Delta Halo: 15:00 minutes
Regret: 15:00 minutes
Sacred Icon: 15:00 minutes
Quarantine Zone: 15:00 minutes
Gravemind: 20:00 minutes
Uprising: 15:00 minutes
High Charity: 15:00 minutes
The Great Journey: 15:00 minutes

Halo 3
Sierra 117: 15:00 minutes
Crow's Nest: 20:00 minutes
Tvaso Highway: 20:00 minutes
The Storm: 15:00 minutes
Floodgate: 15:00 minutes
The Ark: 20:00 minutes
The Covenant: 20:00 minutes
Cortana: 15:00 minutes
Halo: 20:00 minutes

Halo 4
Dawn: 15:00 minutes
Requiem: 15:00 minutes
Forerunner: 20:00 minutes
Infinity: 25:00 minutes
Reclaimer: 20:00 minutes
Shutdown: 20:00 minutes
Composer: 20:00 minutes
Midnight: 25:00 minutes