For obvious reasons, 2020 has been a year of delays, push-backs and much-needed "extra time". It's hard to make anything, let alone complex games with teams dozens (or even hundreds) of members strong. The next game to, understandably, see its release date thrown further down the calendar is Serious Sam 4. Originally planned for a release in August 2020, the game has now been pushed back the following month, specifically, the 24th September.
In the latest trailer (found above) showing a Beheaded Kamikaze enemy literally running through the month of August and into September, developer Croteam assures players that this release date is "for real this time". As far as I'm concerned, if they need more time, they can take it, although their confidence is certainly reassuring.
Serious Sam 4 releases on PC and Stadia 24th September 2020.