Mission Four really cranks the difficulty up for those on their playthrough at becoming a
Metal Slug XX Master. Enemies spawn quite discreetly sometimes, especially the RPG soldiers who like spawning from the top of the screen whilst your busy fighting enemies and vehicles at ground level.
As per usual, take your time, save your prefered weapons for the tougher sections of the mission, and make sure your awareness levels are at an all time high! Check out this video I've put together where I showcase how to make it through this mission without dying.