Pretty unique idea, I really liked it because it adds quite the interesting twist to an already commonly known game concept :)
Overall great work given the available time everything fits well together, the only remark/feedback I would have is if you have more time to try to adapt the mario to maybe make him fit more in with the tetris art style, but I am not 100% sure on this one because then the goal of the theme might not come out that well, besides that an ingame info about the controls would be nice if you add something as I didn't read the description at first :)
Well done :)