You could play Ghost Recon: Wildlands or try some of the older Ghost Recon or Delta force games. Some of the weapons on offer are older in it.
There's a tag on Steam named coop campaign that might help find a few for you. I saw a real time tactics game called War Mongrels that might be of interest though it's obviously not a shooter.
Also, obviously there's "hell let loose" but it's not a campaign experience
I got this scar on my face cause the first game was such a struggle
Monkey Island has aged like a dairy farmer
I've only finished the demo but this is quite a beautiful and charming puzzle adventure and it's worth checking out if that's your thing.
It's also available with a Netflix subscription on mobile and the controls are pretty decent for mobile/touchscreen due to the way movement works in the game.
If you're unsure about it and don't have Netflix, then check out the demo on steam (I'm assuming it's still available).
I would say that I enjoyed controlling it slightly more with a controller/dpad.
I recently discovered shadow tactics which has similar mechanics but with a samurai theme. Quite a cool game.
There is also the more recently released shadow gambit which has a pirate theme.
Is there a sublemmit for gaming memes?
This is some impressive knowledge. How do you know all this?
I would love to see their take on Fallout
2 quite different puzzler games:
This one caught my eye because of the art (same artist as Braid) but the everything about this game is charming
https://store.steampowered.com/app/2596420/Arranger_A_RolePuzzling_Adventure/
Arranger: A Role-Puzzling Adventure follows the story of Jemma, a small-town misfit on a journey of self-discovery. Venturing out beyond her stiflingly cozy confines, she finds an inspiring world - but also one ruled by fear, and a strange, immovable ‘static’ force. Can she disrupt a culture of stagnation, and find a place to fit into it?
This one I played because it's by Game Maker's Toolkit from YouTube so was keen to see what he'd built. Also enjoyed this one and it has a cute and polished presentation style.
https://store.steampowered.com/app/2685900/Mind_Over_Magnet/
Mind Over Magnet: Escape a dangerous factory using the power of magnetism. You must team up with three different magnet friends and use their unique abilities to solve more than 60 tricky single-screen puzzles.
Ah but I was saying that even this game predates helldivers 2. It's been in early access for quite some time
I must confess that I haven't read the book but I had heard the tone is not quite the same
As well as Xbox and Switch according to the trailer