This game was made with PICO-8, a "fantasy console" Virtual Machine with some strict limitations. One of those limitations has always been a restricted 16 color palette.

However, 16 additional colors were recently uncovered. If you're familiar with PICO-8, the original colors have the values 0–15. The new colors have the eighth bit of the color value set as well, which means that you simply add 128 to the original value to get its corresponding secret color. One catch (and the reason this wasn't discovered earlier): You have to change an original color to its secret corresponding color in the screen palette (they're not available in the drawing palette) with something like pal(color_value, color_value + 128, 1).

These are the new colors:

This was perfect for this game! The original Famicase artwork for this game looked like this;

Because of the original PICO-8 palette's lack of blue colors, I had to make my game adaptation look like this:

But with the new palette, I could turn it into this:

Much more faithful to the original artwork.

And that's all, really. Looking forward to seeing what people do with the new palette though!