This game is beautiful - despite being made up of, as you said, untextured cubes, the lighting and composition genuinely make it look gorgeous.  I especially love the torches!  Flames made of cubes.  I'm on a mac and therefore could not download it, so I played in browser and struggled with the mouse.  I opened a few chests, but if there was gameplay beyond that, I missed it.  However, even just opening like 3 chests, it was pretty evocative of discovering treasure in an old space.