Serious Sam on Reddit:
Just in time for your weekend Serious Sam 4 sessions, in comes a brand new exciting update. With this one, we're adding some cool new features like more battles on the vast countryside of France, as well as support for saving your coop progress. Finally, you may say. And you're right.
Don't know why consoles are tagged when it's exclusive to stadia for a year.
SS4 is seriously not that great, the 1st and 2nd ones were so damn good, 3 and this one, not so much.