I've only played a little bit of this genre, with Dog and Goblin, and I'll be honest, it never really clicked with me.
Which is why I want to say that I really enjoyed this take on it! It was simple enough to actually learn the mechanics and not have to worry about crazy interactions and synergies to try to meet the deadline - though it did take a couple of tries to learn which characters would combo with one another well enough to carry into the last deadline.
I think some SFX would really crank this up, they're normally a big hook in these combo building games, since they help activate dopamine receptors or some other human psychology mumbo jumbo.
I would also consider letting the player select an idol to see their active affects when viewing the board, so you can plan what to try to grab in the next idol phase, and maybe you could even display stats for idols that have resources, like Koyori's progress towards next inspiration, or Gura's pop modifiers from eating, etc.
That might be harder to get working, but I think it would help a lot.
Overall though, really great submission, and it sounds like you're looking to keep working on it after the judging period, so I'm looking forward to seeing the updates, great work!