Hey, I like this game and I think it is well put together. I really like the timer that appears when a cube enters the danger zone.
I do have a couple of suggestions. Adding a current score display would help players track their progress in real time, and a high score feature would allow them to keep track of personal bests.
Additionally, providing more options to spend coins would introduce variety and encourage players to experiment with different tactics, making the game even more dynamic and challenging.
Keep it up and good luck!