Is there multiplayer?
Yes, there will be 4 player online multiplayer, with splitscreen available on PC. In 4 player online multiplayer, players can either start a multiplayer journey together or join a friends single player game during the adventure in which case they will take over a companion.
Is there Cross Play?
Direct Connection works between Steam and GOG on PC & Mac.
Is there split screen?
Split screen is available on PC, however it is not available on Steam Deck.