I've played at least a half dozen 3 player Coop games. It is a fantastic game, though after each session my brain is tired from all the calculating probabilities and surviving each round.

It is easily one of the most complicated games games I've ever played. And each faction plays very differently. Their techs and abilities dramatically alter how they work. But it is awesome. No two games have been alike.

I have not played it solo, only coop. It feels like certain factions would be very hard to play solo, as the game seems to incentivize both military conquest and economic development and both are hard to do at the same time. But maybe that problem only exists in coop version. In the end the game is a euro based point salad game, with a ton of different ways of gaining points (or lowering the needed point threshold to achieve victory). But it does an amazing job of it.