Night Slave

Night Slave is a side-scrolling action game very much inspired by Assault Suits Valken. The game starts off by introducing the members of your team, a group of mech-piloting girls from various countries who are assigned a new mission called 'Mission Night Slave'. You begin by investigating an enemy base but it's only a matter of time before the plot takes off, introducing more twists than you'll be able to keep count of -- or even see coming for that matter. (From culture.vg review)

A terrorist organization known as Slave Dog poses a threat to the entire world. Steel Fox is the name of an all-female special squad, highly trained in counter-terrorist combat. Assisting them is the independent, state-unbound corporation Neo Logic, which produces assault suits -basically giant robots with their own heavy weaponry, which can be navigated by a skillful pilot. The young female pilot Rei from the Steel Fox is sent on a decisive mission, codenamed "Night Slave" - an assault on the terrorist base.