Earth Defense Force, is a Single player Japanese Arcade style FPS ...
(not to be confused with the 2D scrolling shooter Earth defense force)
It has RPG style grind elements to get the best weapons ... Because Japan
Later in the game you get to use large battle mechas and stuff ... Also very Japan
In some ways it's mindless and the AI is just plain not responsive, but in other ways, it's deeply satisfying game to just blow things up...

There is also the Strategic element whereby certain classes have severe drawbacks which require you to work around those drawbacks by surgically inserting and removing oneself from key battle points..
FOR example.. The Ranger, the footsoldier class, has medium runspeed, but his weapons are limited to 2x and they either don't do alot of damage, or they do lots of damage but carry UN-Refillable ammo..
So given that, they can't straight up engage the enemy, they have to be more tactical and conserve the power-ammo..