I'm glad you enjoyed the game!
Initially, I had included a legend within the game, but it took up too much screen space and caused visual clutter.
I didn't have enough time to create a cleaner tutorial or hints system since I also had to work on the art, so I decided to use a "How to Play" section on the game's page instead.
However, once the jam is over, I can create an update to improve this aspect of the game! Thank's for the feedback!