Secrets
Camouflage, weapon unlocks, alternate outfits, and everything else Snake earns for making it through Old Sun.
Bandana (Infinite Ammo)
Equipment UnlockA full no-kill run — tranquilizers, CQC holds, and stealth are all fair game, but nobody dies. The reward is the series' signature infinite-ammo item.
- Bandana equip item
- Unlimited ammunition for every weapon while worn
Stealth (Optical Camouflage)
Equipment UnlockEven harder than the no-kill run: get through the entire game without ever letting a guard raise the alarm on you.
- Optical Camo equip item
- Near-total invisibility while equipped
Solar Gun
Weapon UnlockSpare all four members of the Beauty and the Beast Corps instead of killing them, and collect their dolls along the way.
- Solar Gun
- A doll collectible for each Beauty and the Beast Corps member spared
Rail Gun
Weapon UnlockA straightforward reward for finishing Old Snake's story — makes a New Game+ style replay considerably easier against Gekko and armored PMCs.
- Rail Gun available from the start on subsequent playthroughs
Patriot (Infinite-Ammo Rifle)
Weapon UnlockNamed after the Patriots themselves, this rifle is the top prize for the emblem system's toughest challenge run.
- The Patriot: unlimited ammo, no recoil, no reload
Big Boss Extreme Difficulty
Difficulty UnlockThe hardest difficulty in the game, unlocked automatically once you've beaten the story a first time.
- Big Boss Extreme difficulty setting
Alternate Camouflage Patterns
Cosmetic UnlockDozens of face camo and suit patterns are tied to the emblem system's tiered completion requirements, rewarding progressively stricter stealth runs.
- Face paint and OctoCamo patterns based on past Metal Gear protagonists and villains
Best Ending
Story EndingUnlike earlier games in the series, MGS4 doesn't branch into dramatically different endings — but it rewards a full, attentive playthrough with one of the series' longest send-offs.
- Full ending sequence and epilogue