Unfortunately, D:OS Enhanced Edition only supports 2 player co-op. There are a couple mods on PC which can enable 4 players (with some issues, depending on which mod) for online or LAN multiplayer.
D:OS 2 supports 4 player multiplayer, but controller support has not been implemented yet, and currently split screen co-op is not planned. It is also only available on Windows; other platforms may be announced later, after the full release.
