With all the studies of games in the world, I’m amazed there hasn’t been any attempt to figure it out. Given that it’s Greek, my immediate guess from the board and illustration is that it’s a 2-player worker-placement game. The lower board indicates resources based on the color of the circles/spaces, and the upper board with the cones are the advanced resource generators - so you want to basically place workers in the lower circles to put the cones on your side of the board.

That may be opposite - rather that you had cones and they impact the circles.

Given that only the four cones were found, either the other pieces were too valuable to be left, or somehow you’d move the cones from one board to the other (since I’m seeing two separate phases of play).

Just as a note: I’m not a boardgame designer, but I am an avid player of multiple genres of board game.