Lovely! I really enjoy minimalistic designs and I found yours very elegant. It is easy to see that a lot work went into it too. It felt very well balanced too. I found it a bit hard to play on a very large screen (and in the embedded web window because the cursor would go out of focus), but that's inherently trickt with mouse movement controls, I should have probably tweaked my sensitivity.
Very well crafted. I feel like it has a lot of (game) design space to explore, which is always intriguing, but at the same time it is already a great standalone experience.
May I ask if you have a visual design background of some kind?