In A.R.C.S, you should command a squad of mercenaries to protect your base. The game has a trendy gameplay which we're familiar from the popular defense-shooting games even though it looks like a 90's game with its retro graphics and sounds.
Use your MOUSE to aim and fire. Use the left and right ARROW Keys to switch weapons. Up ARROW to manually reload. The crosshair shows the shot radius and ammo.