They also call it there engine on Ion MaidenYet they're headlining "devs of duke nukem".
They're using Darkplaces engine and the newly released Trenchbroom editor from Kristian Duske which helps simplify some of the Quake map editing. Which is also helpfully left out of there news.
They just wanna buy it "BECAUSE ITS THE DUKE DEVS" that's not fair imo.
If you truly want to see some work from the real creators that's recent, Duke 3D World Tour episode 4. They actually profit from it too.