Thank you for playing the game, and giving us this feedback!
If you haven't given it a go already, you might enjoy the free mobile version of the game for iOS and Android, which is currently only singleplayer.
The idea of offering a more coop oriented mode is a great idea! However, we'd want to keep an element of competition. Do you think a team based gamemode would work? With surviving team members able to somehow revive dead ones.