Metal Slug 7 is the eighth entry in the Metal Slug saga and an exclusive to Nintendo's DS handheld system. The player chooses from six different heroes (Marco, Eri, Tarma, Fio, Ralf and Clark) as the embark on a mission to stop the diabolical (and persistent) General Morden as he unleashes hordes of henchman and machinery to stop the player, as well as make allies with a new and more dangerous army in the process.
Like many others in the series, the gameplay is basically the same, having the player using the D-pad to move their character around on the screen and using the "Y" button to fire their primary weapon. The "A" button is used for throwing grenades and the basic melee attack as the player comes in close quarters with an enemy with the "R" button to change their primary weapons.
There are some new melee attacks as well when using the D-Pad and pressing the "Y" button to unleash the attack, each attack differ depending upon the character selected. Also, four characters (Marco, Tarma, Ralf & Clark) have a special attack that can be used by pressing "Up" on the D-Pad and hitting the "L" button and the "Y" button. Along with these new attacks, the game also utilizes the DS' dual screen capabilities with the main game being played on the top screen and a scrollable map on the bottom screen that show's locations of freed POW's and items picked up as well.
The standard power-ups are also present such as heavy machine gun, rocket launcher and laser gun to name a few as well as the ever dangerous "Metal Slugs" that are scattered throughout the seven stages of the game, ranging from the standard tanks to jet fighters and even bi-pedal tanks. There are also three difficulty settings to choose from: Beginner, Normal and Hard.
A new feature is the 80 mission Combat School option which allows players to partake in a series of special missions that will award players depending upon the required action of the stage (ex. some stages will score the player on how many soldiers they destroy while other's will score the player depending on how many POW's they rescue). The better the player does during these missions, the more points they will be awarded and raise their ranking which ranges from "Recruit" to "General of the Army".