Really cool game!
The cube rotating is a neat concept, I liked slaming on it and bringing in spawners and crystals to the surface.
The art is quite nice too, especially the upgrade section.
As others already said, the attacks do feel clunky to execute and I don't know if that is the intention (since there are upgrades to the slams) I found only using the slams to change the sides mostly and not bother with the enemies. Maybe I approached it wrong!
Overall I liked the game hope you expand on it :)