Gun Shot: F+HP
Marco takes a shot with his pistol. Like B.B. Hood's gun attacks, this is a close range thing.
Fire Throttle: QCF+P
Marco does a huge straight punch with his fist surrounded by fire. This slides him forward a step or two.
Sneak Attack: QCB+K
Marco quickly crawls up to his opponent. This goes under mid-level attacks and fireballs, and can be followed by...
Hyper Blast: P during a Sneak Attack
Marco does a double-handed hammer uppercut.
Mega Bomb: HCF+P during a Sneak Attack (close)
Marco grabs his opponent and leaps with them to the edge of the screen, where he slams the poor sap into the wall. Unblockable.
Air Raid: DP+P
This is an anti-air grab. Marco leaps up and suplexes his opponent into the ground with a blast if he grabs him.
Great Slam: QCB, F+P (Close)
This is a Special Throw. Marco piledrives his opponent and finishes ‘em off with an elbow drop.
DDT Bomb: HCB(x2)+P
Marco turns around and runs the opposite direction of his opponent throwing grenades behind him as he goes. If it sounds like a Rollento rip-off, that's because it is :)
Personal War: QCF(x2)+K
Marco begins to punch and kick wildly in place, before he finishes his opponent off with his knife. This is basically Dan's "Certain Victory Relying on No One But Myself Fist" move.
Big Guns: QCF, HCB+P, Any
Once you do this move, Marco will pull out one of the Power Up Guns from the Metal Slug series. If you want to determine what gun you get and not have a random gun, you have to hit an attack during the animation pause. The level determines how long you have your gun and LP shoots the gun straight, while HP shoots it up.
LP=Laser Gun: When you fire this gun, you shoot a thin laser beam that can be held out as long as you hold the punch button. But you can't move as you hold it out.
HP=Flame Thrower: This gun spits out a burst of fire every time you press punch. It has medium range and medium power for the guns, but has little delay time.
K=Shotgun: This is the most powerful gun you can get. The range is the shortest of all of them, though, and it has pretty bad delay time when you shoot.
Power Up Mode: Marco and his Big Bad Tank
Effect: Marco climbs into a walking tank, like the one in Stage 2 of MS 2, and P attacks become machine gun attacks that can be aimed, and K attacks become grenades.
Downfall: A couple of hits is all you need to lose the tank.