Good golly, voice acting (in a game jam entry!) always blows me away. Great work there.
Some of the art was super cool, especially the backgrounds and the player character. I also loved all the little things that would move around in the backgrounds, great details. But sometimes it seemed to lack some cohesion. For example, Hephaestus seemed weirdly huge and had an outline...?
The story and world really draws you in because you've done a good job building it. I don't know that the big exposition dump from Hephaestus is totally necessary, but it's not terrible. The writing is pretty good!
Overall, this is shockingly fleshed out. Could just use some polish and refining. Excellent entry!