Re-enlist today!
The graphics are still crisp and beautfully Metal-Sluggish. Now, however, the environments are lusher, enemies better looking, and there is more than one actual weapon graphic.
The weapons are still mostly the same, but the ammo is a bit more abundant now. When you switch guns, the little character changes weapons, too, instead of using a "5-in-one" gun. The flamethrower is actually useful, with a far-reaching inferno. The grenades have a delayed fuse, so more skill is involved. There is even an automatically deployed knife that slices and dices nearby foes. Speaking of foes...
The enemies are even deadlier, now. They can shoot all over the screen, kick you, and toss grenades. Some have machetes or kitanas to turn you into chopped liver. But they all are improved.
The gameplay is the same, but with a few additions. A Chop-Lifter style minigame adds fun, as do some tank sequences (like in Metal Slug). You can roll, now, approaching enemies while crouched. But each area has new threats, like a fight on a train, or on the back of a speeding truck. Either way, this game is simply unmatched.
Last Words: One of the Greatest GBA Games ever. Buy it ASAP. If you like this, I'd buy the original, too. Both are at a discount price (you can get both for under $10)