Snake sneaks through the portal into the ship’s interior, his radar showing danger on the path that lies before him.

Killing those he confronts would be the easy approach, but likely would lead to greater danger. However the danger he faces is of his own choosing. Stealth is his guide, and the group he works for, Philanthropy, is after information, not a kill rate. It would help if the enemy felt the same way.

Metal Gear Solid 2: Substance, a Konami release for the PlayStation2, is an addictive linear shooter romp through dangerous waters. What make the game so strong are the graphical elements, and the way the game pulls players into the tension of the situation.

The first scenario has Snake on the deck of a ship on the Hudson River. The ship is apparently carrying the latest in Metal Gear technology (a weapons’ system that is devastating, though the latter version is more powerful than the others to date), and is guarded by U.S. Marines. Snake’s job is to sneak into the ship’s hold, get pictures of the machine, and then get those pictures back to Otacon (his contact with Philanthropy). But just as he is about to make his move, Russian troops descend from the maelstrom, kill the Marines and take over the ship. These guys aren’t playing fair, and the mission just got tougher.

This might ring a bell for Metal Gear fans, and there is a reason for that ­ it is. This is Metal Gear Solid 2: Sons of Liberty, but with new game modes, hidden playable characters and some new storylines.

The game’s new features include 350 virtual reality missions and 150 alternative missions; five new Snake stories; as well as continuing the Sons of Liberty story while adding the Casting Theater and Boss Survival modes of play; and a skateboarding mode which allows players to explore the Big Shell as either Raiden or Snake.

Alternative missions really tweak the adventure. In the Hold Up Mode, you have to literally hold up all enemy soldiers.  There is also a timed mission like the Photograph Mode, and Elimination Mode is actually tasking you to wipe out the enemy.

Certainly the game may not appeal to fans of Sons of Liberty because, in essence, it is an expansion pack. But it is loaded with new missions and certainly any gamer not familiar with the series will find this an addictive and thrilling introduction to the game.

Hideo Kojima’s game is certainly well designed. It is loaded with cutscenes, with dialogue that is ­ at times ­ somewhat lame because of the backstory it tries to cover, but these cutscenes are a nice precursor to the action, which follows.

As Snake makes his way from the downpour on the ship’s deck to the interior, shadows show where the enemy is in relationship to the corners. He also leaves behind wet footprints on the deck of the ship.

It is that kind of attention to graphical detail that makes this game so exceptional. While most of the game is played from a fixed camera that is located above and behind the action, you can also switch to first-person mode quickly for a better view of the situation. First person will reveal things you may otherwise miss.

The soundtrack of this game is also excellent. The musical score lays the perfect frame for the action, and the vocal characterizations are well done. With the array of difficulty options, this is a game that will appeal to players of all skills.

While Substance is, more or less, an expanded version of Sons of Liberty, the game should appeal to players who have never seen the series, but like action games, as well as Sons of Liberty fans who are looking to extend the experience. This is a well-made game, loaded with options, adventure and adrenaline-pumping action.

This game is rated Mature for blood and gore, partial nudity and violence.

Gameplay: 9.2
The action is flawless and load times as you move through the mission maps is negligible. The controls take a little time to get very comfortable with, and some action elements that would make the game easier are noticeably absent, which forces game players to use their brains to get to the arcade-style power ups.

Graphics: 9.5
This game looks amazing. From the special effects to the dynamic lighting and shadowing, the attention to detail makes this one of the best-looking PS2 games in its genre. A rotatable camera would have been nice.

Sound: 9.2
The voice acting is solid and the musical score is perfect for the tempo of the game.

Difficulty: Medium
There is a full array of difficulty levels to challenge players of all levels. Control elements may take 10 minutes to get comfortable with.

Concept: 8.8
This is an expanded version of Sons of Liberty. It can be argued that these elements should have, or could have, been in place in the original version. But that game stands on its own as a remarkable achievement. This is an old-friend revisited with some new accoutrements.

Overall: 9.3
Metal Gear Solid 2: Sons of Liberty was a winner. Substance is simply adding that ­ substance to the title that serves as the basis and core for the game. There is more here to do, and a broader experience to be gained. Yes, the missions are somewhat linear in nature, but the clear-cut objectives force it to be so. Substance is well designed, tremendous graphically and in the audio department, and a great, addictive ride.