Metal Gear Solid: Portable Ops finally brought classic Metal Gear Solid gameplay to the PSP. Described as the missing link between MGS3 and the original Metal Gear, the game once again sees you take control of Naked Snake, only this time you must recruit soldiers to your side to fight against the renegade FOX unit and save the world from the threat of the first Metal Gear - RAXA. The European version had an extremely delayed release, which in turn gave it additional content to try and put right the lengthy delay. These new features were all rather poor and included a boss rush mode, where players could fight the bosses one after another. Also included were special camouflage soldiers, wearing camo patterns of the flags for various european countries aswell as new additional side missions and soldier careers.

After initially being released, many copies of MPO had to be recalled due to there being no BBFC rating logo on the disc. As such, there are technically two versions of the MPO UMD. The one without the BBFC logo is seen as the more "desireable" version, due to it's rarity.