how does coop work in this?

[vanster__]

I never have played any gears games at all but I am currently looking for an rpg shooter coop game that I can play with my friend together. How much content (game itime) does this offer? What are the pros and cons? Do i need a controller for this? I just need some basic infos i guess. Could also watch a yt video but i don't wanna get spoiled from the gameplay itself, Just need to know if its playable at all kinda. (mostly story wise with a friend like in Halo or Crysis as an example)

[Q̴̡̼̽̒̕u̸̘̪̾͊̚͜e̴]

The full campaign is co-op, from start to finish.
Not an RPG though, third-person cover based shooter.

I don't know if you're trying to play together on the same PC - But me and my buddies use mouse + keyboard online (you can use a controller if you want)