Metal Gear Solid 2: Sons of Liberty was released for the PlayStation 2 in late 2001 in North America and China, and then in March 2002 in Europe. Metal Gear Solid 2: Substance, an expanded version like Metal Gear Solid: Intergral, was released in 2002 and 2003 for the PlayStation 2, Microsoft Xbox, and Windows PC.
Metal Gear Solid 2: Substance included the original game as well as various added modes, including Boss Survival mode and Casting Theater mode, which were both included in the Japanese and European releases of the original game.
A new mode called Snake Tales attempts to fix one of the main criticisms of the game – which was replacing Solid Snake with a new protagonist, Raiden. Snake Tales offers five story-based missions where you get to play as Solid Snake and they feature characters such as Fatman, Vamp, Emma Emmerich, and Solidus Snake. Meryl Silverburgh makes a surprise appearance, replacing Olga Gurlukovich as one of the bosses on the tanker. Of course, none of these missions are part of the official Metal Gear canon.
One of the sillier added modes was a skateboarding mode, based on the Konami game Evolution Skateboarding. In this mode, the player can play as either Solid Snake or Raiden as they skate around various Big Shell-themed levels, completing objectives.
Like Metal Gear Solid: Integral, Metal Gear Solid 2: Substance features several training missions, this time over five hundred. Three hundred of these take place in a computer-generated environment, just like the VR missions in integral, which the other two hundred take place in environments taken from the main game.
These missions can be done as either Solid Snake or Raiden as the player complete various objectives that include target practice, bomb disposal, eliminating enemies, and of course, stealth.