The iPhone/iPad and Android are already home to a fine port of Metal Slug 3, one of the best entries in SNK's arcade run-and-gun shoot-em-up series. Now the Japanese game maker has ported the original Metal Slug to mobile devices under the highly appropriate title Metal Slug 1. Like the previous port, this one boasts several enhancements like an all-new Mission Mode and of course, Bluetooth co-op play. New for this installment: adjustable controls.