Is there anyways to play this game co-op with a friend?

[PolishSlay3r]

Is there any mod or something we can download to play it together?

[Шейдула Лентяй!]

idk. seems strange, you only gonna disturb each other's gameplay. but there are too many dif mods, so try to check

[ryanrem]

There are mods for the game, this a video explaining the multiplayer mod for it
https://www.youtube.com/watch?v=82ag5mpM3NM