Just like the previous version, the game is very polished and feels great to play. I wishlisted it right away and hope there's a lot of additional content that goes beyond the demo. But I also want to add my two cents regarding the balance of the game.
I know this will come off as a bit strong, but I've been getting this nagging feeling that there is pretty much no depth to the game. As far as I can tell, there are only a handful of strategies that can get you all the way to the end. While the rest, even if they turn out optimally (which they don't most of the time), will fall apart 3/4 in. Or even way before that.
Most cards simply don't scale quickly enough to keep up with the increasing requirements. Sometimes I feel like I'd need about 3-4 additional levels before I could actually get a proper engine running. The runs are simply too short and don't allow you to mess up in any way. Which makes most strategies useless if you actually want to finish the game.
I'm not sure if this is a case of "the game is simply difficult". Because almost every single time I lose I feel like I didn't even stand a chance. So I just repeat the same two strategies over and over that actually do work. But they are so much better than everything else that I'm not sure this can be fixed by changing some numbers. There's a fundamental design issue here where the gameplay loop doesn't allow for any cards that don't scale by least 50% every single round.
Additionally, I'm a bit disappointed with the variety of synergies. The strategies seem to be very clear-cut and I haven't found a single interesting synergy so far. It always feels like you're trying to get to the exact same endgame build. The available cards are simply to specific and require very specific other cards to get to their full potential. I feel like there should be a more "freeform" approach to card design, that allows you to actually mix and match different cards. Right now, as soon as I pick my first card, 90% of the other cards become mostly useless.
I realize this seems like a lot of negativity, but I really like the game and want it to succeed. So I hope this helped in one way or another.
By the way, not sure if it's just me, but this whole "flow state" things strikes me as really weird. Not sure why you chose to go with that angle.