Metal Slug Mobile 3 is a Run-n-gun game made by SNK Playmore for various cellphone models. It is an enhanced American port of Metal Slug: Allen's Battle Chronicles.

A new enemy has appeared on the horizon in the shape of a relentless zombie army. Just as Sgt. Allen O'Neil of the Rebellion Armed Forces is about to engage them in battle, he realizes that they are in fact his own soldiers. With no way to communicate with the zombies, no time to find another solution, and no way to call for backup, it appears that Allen has little choice but to fight his once loyal troops. Luckily for Allen, being a notorious bad guy means he has a huge cache of devastating weapons at his disposal...