"Gilgamesh" the anime series from 2003 is difficult to describe. The mood of it is like that of a long, dull nightmare.

There is almost no spectacle. The whole show is just grey, full of grim faces staring into the middle distance. It takes a while to acclimate and start to "see" the characters.

Combat and superpowers are present. However, they are largely just backdrop for the true story.

It's not gross nor explicit, but still remarkably heavy.

The main point is exploration of tragedy and supernatural mystery. I don't recommend watching it in a happy mood for fun.