General suggestions/opinions below:
(Also: LOVING this game so far - artwork is beautiful, combat is fun/smooth, story aspects are awesome, cards are awesome).
Suggestions for Deck Builder feature:
When you are in the deckbuilder and hovering over waiting for them to appear, they appear directly over the cards in your current deck. Moving these hovers to the left would be beneficial in looking at cards easier. Also clicking these cards doesn't do anything. Its not exactly clear how to add/remove cards from your deck at first. Maybe clicking a card in the right hand column to remove would make this easier for the user. And clicking cards in your library would add them to your deck would speed this up.
Difficulty -
I think the difficulty level of the game is pretty tough as of now. I know its a rougelike and its supposed to be challenging but i think the AI difficulty level scales up considerably once you get to the second map and becomes REALLY hard. I've played this game about 8 times and have only finished till the end of the early access campaign twice. 60% on losses due to resources, 40% due to battle.
Resources -
This is my least favorite part of the game as of now and overall i think needs to be more balanced. Losing this way after getting some great cards is really tough. Not being able to reload at the beginning of your existing map and having to start from the beginning feels bad. If you're working towards a good deck, this can be erased by resources depleting because you're fighting too much or taking the long way to the end. Might be cool if their was an alternate mode or something? Like casual mode and rougelike mode? Thoughts.
Saving:
Sometimes when starting a few of the first points on the map the "enter combat mode" screen freezes which forces the player to exit to the menu manually. When trying to load from this position, the save state is corrupted, not allowing you to pick up where you left off. If you had a good start, this can be a bummer. Probably a bug but i figured was worth mentioning. Otherwise, after the first couple of points of the map are reached, this doesn't happen at all and saving works fine.
Tablets/Phones - general thoughts
Not sure if this is on the roadmap but i feel like this game would play great on tablets and smartphones. Honestly, this would be my favorite phone game were it available for me to play on the train every day.
Overall I'm really LOVING the game though. I never leave feedback like this for games in dev but i can see myself playing this game a lot upon its final release. Really excited to see the final product and evolution of the game!