Modder sultim_t redesigned the shooter Serious Sam: The First Encounter 2001 and added support for ray tracing to the engine. You can download the updated version here by this linkhowever you will still need the original game.
At the same time, sultim_t released a trailer, which clearly showed the benefits of new technologies:
Serious Sam TFE: Ray Traced Is a ported version of the classic game Serious Sam: The First Encounter (2001), which includes a redesigned graphics engine with ray tracing support. Hardware-accelerated ray tracing can calculate global illumination, reflections, refractions, soft shadows, and other visual effects in real time.
It’s great that enthusiasts give classic games a second wind.