Hello Stratezo, and thank you so much for this! It's clear you really played the game and thought about it, and that's the best kind of feedback a dev can get. I'm glad the dialogue and music worked for you, and a battle track is a fair point.
Card balance: you're right. Some cards aren't worth their cost, and Nyxara is the clearest case. Most of this first release went into building all the systems around the cards, which was a logistical nightmare!!!!!, so the balance got less attention than it needed. A proper rebalance is planned for the next update.
Rosie: honestly, you surprised me. She wasn't supposed to be killable. The wager is meant to be lost, and I even left an item that restores Action Points out of the demo on purpose so beating her would be close to impossible. You found a way anyway, so I'll lock it down better. Your idea of a time limit, so players can't grind endlessly in the starting area, is a good one, and I'll keep it in mind.
The rest is noted too, including the "new quest" tag.
All of this goes into the update I'm already working on. Thanks again, and it's great to hear from someone who likes card games as much as I do!
Cheers!!