For the 1st rule ("Your game must be 2D"), does it mean visually 2D, mechanically 2D, both, up to interpretation, or?

Hey :) It sort of means that it must be visually 2D, but you can also submit a game with 3D art and 2D movement if you want. But be aware some people might rate it harshly due to not being "pure" 2D.

Theo