Do I even need to say that the polish and art quality of this game is ridiculous? It's so good that it doesn't feel like a jam game in the slightest, that's the highest praise I could possibly give. You could ship a game with this level of polish and it would stand out as a really nicely produced games among dozens of games that people worked on for months.
As for the actual gameplay: the puzzles are really cool. I've personally never seen this mechanic before and I thought it offered a nice level of challenge. There were definitely a few aha moments. A bit of a downside was, that by the time I had figured out how the puzzles generally worked, the biggest challenge became looking at the pixels on the cake and figuring out which color was the base color and which was the one that comes after. If you continue working on this, you could maybe add different shapes which can be combined in various ways to make the same shape. Something like this: 