Design wise Marathon 2026 has a more distinct art direction than the previous games. It’s not a “Doom Clone” anymore but it did inspire Halo, and a lot of elements from Halo would never exist without Marathon first existing, even Master Chief. But in this day and age Nu-Marathon is just the step in the right direction for the franchise as a whole IMO. Maybe they’ll tackle a narrative driven game if marathon succeeds enough, and it already seems like it is, so there’s that.