Main Ops are Campaign missions to undertake toward story completion of Peacewalker. Main Ops may only be entered as Snake (Big Boss) the first playthrough, but may be accessed by other Combat Unit assigned characters once a mission is completed at least once.
Some main Ops Missions may have restrictions on items, number of Cooperative players available, (1-4 players) or may restrict use of characters to Snake only.
Mission Ranks are graded based on stealth up to a highest possible rank of S. Rewards for mission completion may occasionally be achieved after a mission is completed, or once a mission has been completed with an S rank. Also, there are hidden items in many levels known as Confidential Documents. These items partially unlock new Items or Weapons for Snake to use, though they must often undergo Research and Development from captured soldiers or volunteers assigned to the R&D at Militaires Sans Frontieres (MSF) mother base.
- Walkthrough entries are focused toward single player completion.
Post-Game Activities Edit
Here's a few things to do after you've "Beat the game", i.e. Cleared the final Main Op mission (ZEKE Battle).
- Obtain Strangelove's extra tapes (battle Chrysalis a second time and press Triangle when prompted while extracting AI memory boards). Listen to EVA tell more of The Boss' back-story in Strangelove's Data Files.
- Obtain Paz's extra tapes (battle all the Mark II AI mechs)
- See the female unique characters in their underwear (get an S rank on Extra Op 67)
- Talk with The End in Extra Op 62
- Complete all the Extra Ops.
- Complete all the Outer Ops