I agree with the other commenters that the gameplay loop isn't particularly varied. However, I enjoyed it anyways. I felt like I got into a flow state, especially as things speed up.
My only real comment is that it felt that the inclusion of the dice theme was solely for aesthetic reasons, and it did not seem central to the gameplay. It was satisfying to roll all the coin dice, but it wasn't a necessary inclusion, since the enemies may as well have dropped 1-6 coins each immediately. Same thing with the health values of the enemies. I guess what I'm trying to say is that there was no meaningful randomness in the gameplay. This is not a bad thing, necessarily, just something I noticed.
Also, after buying all the upgrades, it would have been nice to see some kind of "You Win!" message, before continuing endlessly. Just a small change to make it feel complete.