A friend an I just remembered these games existed, and we really enjoyed them when we were younger. Thing is, we don’t know of any place to get them on PC, much less where we could get co-op working. Is this a series that can be played co-op on PC? In any way?
Seems like they were console only games, so you’d have to try with an emulator. Look at compatibility pages such as https://wiki.rpcs3.net/index.php?title=Army_of_TWO for example, while taking note of any special options you need to enable to get it to work.
The patches there makes it sound like there are custom servers to play multiplayer on a network connection. But I have no further insight into how well the game works or if such private server software even exists.
Probably have to emulate and play local co-op but not sure if that would work. That’s your best shot.