If you've ever thought, "Why don't they make a first-person shooter where the main character has four arms?" "The Darkness II" might be your game.

If I tell you to start ticking off this fall’s most hyped video game sequels, there’s a chance you’ll be naming games for a while before you make your way to “The Darkness II.”

“The Darkness,” based on the comic book series of the same name, didn’t exactly set sales charts ablaze during the summer of 2007, but the tale of a 21-year-old who suddenly finds himself with two vicious, tentacle-like “demon arms” and other violent powers found a cult audience. The single-player portion of the game won praise for its mature themes and gritty story.

Like a lot of fans of games that weave a good tale, I picked up “The Darkness” at a discount, and it’s been sitting on my “to play” pile ever since. After getting a look at “The Darkness II” semi-recently, I’m hoping to find time to sit down with the first game before the sequel arrives Oct. 4 on PC, Xbox 360 and PlayStation 3.

Jackie Estacado, the low-level Mafioso turned mob boss in the first game, is back for another go-round, though a number of things have changed. First, “The Darkness II” isn’t being developed by Starbreeze Studios, who made the first game. Instead, publisher 2K Games has contracted development to Digital Extremes, a studio known for its work on the multiplayer component of “BioShock 2” and the PS3 port of the first “BioShock.”

The action picks up two years after the end of the first game, with Jackie having become a Mafia don. As you might expect, a number of people are out to bring Jackie down, and not for the usual reasons of wanting to take his place atop the seedy underworld.

No, some bad guys know all about the titular Darkness living within Jackie, and they want it for themselves. The demo I watched began with Jackie having been taken prisoner and being tortured while nailed to a cross, in hopes that he’ll surrender the Darkness. (Apparently he can give it up, but it has to be done willingly.)

From there, I saw a number of action sequences, mainly designed to showcase what Digital Extremes is doing to overhaul Jackie’s demon arms in the sequel.

Lead Designer Tom Galt explained to me that in the first game, the demon arms were a selectable power. Even though Jackie had two perfectly good human arms, the player couldn’t really use them in tandem with the demon arms.

That’s changed in the sequel. If you’re playing with the Xbox 360 controller, you’ll use the triggers to fire guns and perform other actions with Jackie’s human arms. The shoulder, or bumper, buttons will control the eel-like demon arms. By using the two in concert, you’ll be able to, say, rip a door off of a car with one of Jackie’s demon arms, then use that car door for cover while firing a gun with your human arm.

The game will feature a grisly, ultraviolent combo-kill system, where you’ll be able to execute enemies with demon-arm moves performed via bumper-button taps and contextual movement of your controller’s thumbsticks. I’ll spare you the gory details, but with names like “Wishbone,” “Daisy Pop” and “Anaconda,” you can imagine where Digital Extremes is going with this.

The impish Darkling provides comic relief and apparently occasionally chews off people's faces.

The folks at Digital Extremes also showed off The Darkling, a sort of little helper imp. While the first game had multiple darklings that were controlled sort of like the minions in “Overlord,” “The Darkness II” has one Darkling who provides assistance and comic relief. He’s connected with some of the game’s plot points and can help distract enemies and even occasionally kill them.

As you might expect from a game called “The Darkness,” Jackie’s powers are really only effective when he’s out of the light. His demon arms and ability to regenerate health can only be used in dark areas. In the short bit of gameplay I saw, I could see how important it would be for Jackie to make sure he eliminated sources of illumination, or lured enemies into the shadows for the kill.

Plotwise, Digital Extremes is working with comic book writer Paul Jenkins, who worked on the first “Darkness” as well as the comic book series on which the games are based. Galt described the first game as “one of the first really good, narratively driven first-person shooters,” and it’s clear the team is targeting the same goal with the sequel.

In a brief interview, Galt told me the team wants to explore “what it means for Jackie to have a demon in his head … what it does to him as a man.” If done right, his demonic corruption, as well as lingering feelings of guilt and helplessness over the death of a key character in the first game, should give him a humanity and depth lacking in a lot of first-person shooter protagonists.

As for the game’s secondary characters, I asked Galt what it meant for the men who work for Jackie. If I found out my boss could sprout demon arms that rip apart dissenters in seconds flat, I’d be conflicted about whether to seek other employment, and risk calling down his wrath, or stay close by and do everything I could to help.

Galt described Jackie’s henchmen as being governed by the same self-preservation instincts, even if they don’t fully understand the Darkness.

“They know there’s something special about him,” Galt said. “They’re kind of scared of it, but they respect it.”