Serious Sam 4: Planet Badass is currently in development for the PC, Croteam announced at the Reboot Develop conference yesterday.
Right now there's not an awful lot to go on in terms of game info, although the developer did reveal a trailer for you to gawk at below. Fortunately we won't have to wait too long to find out more details, as Serious Sam 4 will be strutting its stuff at E3 2018 in June.
Serious Sam launched back in 2001 and quickly made a name for itself in the first-person shooter space, having more in common with old school titles by focusing on balls-to-the-walls action over storytelling. If you're more the kind of person who believes in action speaking louder than words, then Serious Sam should be right up your street.
If that doesn't give you enough of an idea of what's on offer, then keep this in mind: Serious Sam 4's trailer features a headless, kamikazee chap with bombs in place of actual hands. Need I say more?