Armor...
	Skulls...
	Various Achievements...

Besides the standard Bubble Shield that deploys a ten second dome shield as protection against enemy fire, the following armor is also available. Each of them have various recharge times.

Overshield (500 credits)
Instant shield recharge and invincible for 8 seconds.

Seeker Drone (750 credits)
Explosive homing drone that remains active for 10 seconds.

Airstrike (1,000 credits)
Several explosives that last for 2.5 seconds.

You can equip up to two skulls per mission. When a mission is completed with skulls activated, you will receive a credit bonus. Having two skulls equipped increases the credit bonus. Skulls will handicap you with the following effects.

Hollow
Your Spartan only has a shield for protection.

Pacifist
Your Spartan's armor and shields deplete when you fire a weapon.

Famine
Dropped weapons carry less ammunition.

Black Eye
Your shields only recharge after taking melee attack damage.

Thunderstorm
Adds tougher enemies.

Blind
Cannot see important HUD elements, including ammo for all weapons.

Complete the following achievements to unlock Microsoft Gamerscore points.

Achievement	How to unlock
Battle Hardened (20 points)	Earn all Gold stars in Operations A through E.
Beam Dance (5 points)	Complete Operation D, Mission 5 without getting hit by a Focus Turret.
Big Spender (20 points)	Spend 10,000 credits on loadout upgrades.
Experienced (5 points)	Earn your first Gold star.
GEN2 (10 points)	Use every Armor Ability at least once.
Home Sweet Home (10 points)	Complete Operation D.
Homing in (10 points)	Complete Operation B.
I Am Your Shield (5 points)	Keep the Elephant 100% intact in Operation A, Mission 3.
Mine Sweeper (5 points)	Do not get hit by any Proximity Mines in Operation E, Mission 2.
Night Knight (5 points)	Do not allow the Watchers to resurrect any Knights in Operation C, Mission 4.
No Loose Ends (10 points)	Complete Operation E.
Not a Scratch (5 points)	Keep the Wraith 100% intact in Operation B, Mission 4.
Ready for Departure (10 points)	Complete Operation C.
Thorough (20 points)	Complete all Assault Ops for Operations A through E.
Vidmaster Challenge A (10 points)	Complete Operation A, Mission 6 with the Blind and Thunderstorm Skulls active.
Vidmaster Challenge B (10 points)	Complete Operation B, Mission 6 with the Hollow and Pacifist Skulls active.
Vidmaster Challenge C (10 points)	Complete Operation C, Mission 6 with the Black Eye and Pacifist Skulls active.
Vidmaster Challenge D (10 points)	Complete Operation D, Mission 6 with the Famine and Thunderstorm Skulls active.
Vidmaster Challenge E (10 points)	Complete Operation E, Mission 6 with the Hollow and Black Eye Skulls active.
Welcome to New Mombasa (10 points)	Complete Operation A.