It has been confirmed now that Serious Sam 4 is coming out on September 24. The game was intentionally meant to come out in August. This update which came in the form of a tweet now confirms the date it is coming out. The game will be coming out on PC and Stadia.
Many people are looking forward to Serious Sam 4 especially since the Serious Sam collection was a Stadia Pro game. Serious Sam Collection being a pro game introduced people into the series. While the delay is unfortunate at least we have a solid date for when the game will come out.