I just tried some 4-player games. It was awesome, but not without bugs:
All my opponents have the same portrait as player 2 despite me giving them different portraits.
Trying to quit a game proved challenging. I clicked the
X in the Game tab to close it but the game kept going on without me for quite some time.
I don't understand how the turn order works. It went P4 -> P3 -> me -> P2.
Whenever one of my opponents was eliminated, their stuff stays visible instead of getting exiled. I can't interact with it anymore but it is a bit confusing.
It's hard to tell who's getting attacked by what. Arrows would be nice.
When declaring attackers, I clicked P3's portrait and then Alpha Strike, and all my dudes attacked P2.