Hey man, I think you could give this just a bit more elbow greese and really make this experience better. First I would add in sounds you can find tons of free sounds online to use royalty free. Suggestions would be to make when the mushrooms finish growing have a poping sound, also I would  try to find some nice relaxing or fun and playful music for the background. Perhaps you could also make this setting seem more like a green room. Adding in an animation of pouring water on the mushrooms could be cool. This was made with unity and this game jam allows asset so there are tons of free models in the unity play store I would try finding some stuff to use. Maybe also make a cosmetic store with the money you get? Just some ideas man! Awesome job on your first game jam game!