First thing first,
Serious Sam 4: Planet Badass won't feature a single desert level. Croteam revealed this ground-breaking information during the opening of Reboot Develop 2018 in Dubrovnik, Croatia. That's right, Serious Sam is back and more badass than ever in the first trailer, cruising through the countryside on a massive motorcycle and killing fan-favourite Beheaded Kamikazes at the seme time.
“In the past seven years Croteam has released six new game projects. But we always get asked the same question: where is Serious Sam?” said Croteam’s co-founder in the opening keynote of Reboot Develop. “I can reveal that this June, at the Devolver Digital conference at E3, they will ask that question no more.” The game runs on the Serious Engine which was used in The Talos Principle.
According to the game's Steam page, "Serious Sam 4: Planet Badass reignites the classic series and takes you on an adventure full of bullets, guts, and one-liners." The last chapter of Sam's saga, Serious Sam 3: BFE was released seven years ago for Microsoft Windows, Xbox 360, PlayStation 3, Android, Linux, Mac OS, so there's a chance that Planet Badass will also be available on today's consoles.