Many of the gameplay innovations commonly attributed to Metal Gear Solid were in fact introduced eight years earlier by its direct predecessor Metal Gear 2: Solid Snake, which was never released outside of Japan until it was packaged with Metal Gear Solid 3: Subsistence in 2006. As such, Retro Gamer regards Metal Gear 2 to be "as close as anyone can get to playing Metal Gear Solid in 2D." Many fans also believed that Metal Gear Solid was a remake of Metal Gear 2. Some of the gameplay and plot elements in Metal Gear 2 that were later used again in its sequel Metal Gear Solid include: