Story, writing, the lore exploration and interesting characters were all amazing. The game play itself lacked a lot. It was thoroughly unbalanced and really not great. Most of my battles were really boring to the point where I'd play one or two cards, and just pass. I knew I'd win anyway - primarily because the cards were so ridiculously OP.
That said, creating a story mode with unique stories and new lore would be really nice. This could for instance be the perspective of the Wild Hunt trying to hunt down Ciri. Or perhaps a story where you take the perspective of Emhyr during the civil war / invasion of the North. What I liked the most about Throne Breaker was how the choices actually mattered, and if they create a new story then I hope they will continue with that.