Thanks a lot for your feedback ! You're not the first who didn't know you can attack with more than one assistant at a time. I tried to get more emphasis on it in the tutorial but it wasn't enough visibly.
Did you try out the second part of the tutorial with the cauldron mechanic ? The game is supposed to be played like that so the first real fight can get a bit stale since there's a mechanic missing.
I'm not totally seduced by the pumpkin mechanic either but even if it's not super engaging it works with the rest of the system so I keep it for lack of anything better.
The roster for the first fight can make the fight drag pretty long, I'll try to adjust it to prevent having these long fights. Fun fact, if you know what you're doing, you can easily win this fight "turn 4" making it only last 30 seconds. But it might be pretty hard to see for new players.