A few thoughts:
The name is great and the animation at the end was cool
I had trouble initially understanding that the idea was to match the color on the right half of the circle (in wordle the hidden secret is what I’m guessing, so I didn’t expect it to be shown)
The percent amount in the mix wasn’t obvious. Your UI and tutorial were helpful in hindsight but I still didn’t get it initially.
I struggled with the last box because the mix is so small it had little effect. This was definitely not fun!
The contrast of % text is hard to read.
A few ideas:
Consider if it might be more fun to have people guess HSL (a row of hue, a row of saturation, and a row of luminance in the “color keyboard”). This is easier to understand than percent mix and might teach people about color! As a bonus you could then hide the goal color as now the guesses would get closer organically
As a separate idea, consider using the web color names somehow. They are quite enjoyable and I could imagine them being fun if you found a way to use them.
Consider making it dark gray background instead of white (I found the lighter color a bit glaring)
Thanks for sharing!