Metal Gear, despite its serious tone, has a few fun secrets and references for observant players.

- The 'Metal Gear 2' Hint: In some versions of the game, after defeating Big Boss, a message appears hinting at a 'Metal Gear 2' with a different protagonist. This was a subtle nod to the future of the series.
- Hidden Developer Message: In extremely rare instances, or specific versions, there might be a hidden message from the developers if you perform a very specific sequence of actions or reach a certain obscure area. These are often hard to trigger.
- The 'Wrong Way' Death: If you try to exit the very first screen by going south (back to the landing zone), you'll often get a game over message from Big Boss, scolding you for trying to abandon the mission.
- The Cardboard Box's True Power: While a common stealth item, the sheer absurdity of hiding in a cardboard box and fooling highly trained guards became a running gag and iconic element of the Metal Gear series.
These small details add to the charm and legacy of Metal Gear, showcasing the developers' creativity even in the early days of gaming.
Compare easter eggs & fun facts inMetal Gear 2: Solid Snake