Very simple game, but the concept is not bad =). Making a multiplayer game for a jam is ballsy, but it's possible to play it alone enough to have an idea of what it looks like and that's great !
I don't understand the relationship with the theme... Yeah, we push cubes, but the "dice roll" doesn't seem to influence the gameplay at all ^^'.
The game need a bit of polishing (that's normal for a 50h game jam), notably adding some sounds, music and ambiance.
Good job =)