So I have been playing a lot of slay the spire 2, I just passed 200 games and have gotten to around a 70% A10 winrate on every character except ironclad (where I am in the gutter at 30%, how do you play this character if you don't get the vulnerable cards? How do you play the vulnerable cards against aeonglass with 3 artefact?).
I've been entirely on the beta branch for context.
This game fascinates me, it's one of if not the best strategy games I have played. Feedback for most things is extremely salient, you makes a judgement call and then a turn or 2 later you have lost N or N+M health and can evaluate your tactics. The thing that keeps me coming back though is the less salient stuff, the layers and layers of thinking to pathing.
As I improve (I would consider myself approaching mediocre at the game, I think 90% winrate is when you can probably say you are good) I find myself evaluating turns on a much deeper level, asking questions like "the elite that's coming up has a big attack on turn 3, given that and how many skills I play each turn what number should tuning fork be on so that it goes off that turn?"
I think people think of the game as requiring luck but my experience seems to be outside of rare occurrences (like an awful 1-in-a-large-number shuffle against a boss you struggle at) luck is not usually a major factor. If I don't die in the first few floors of act 1 (or reach a state I cannot recover from because I am bad) I usually die on the act 3 second boss.
One of my favourite aspects is how A10 forces you to build for all 3 act 3 bosses, since there is a 2/3 chance you face them. This really tickles your brain to get you to think of how you're going to make your deck do everything it needs to win.
My one criticism of the game is that almost all the interesting enemies are in act 1, although with the recent (oppressive, halp!) changes to infested prism and aeonglass I think that things are on the right track.
If you're into deck builders, or just marvelous strategy games, I unreservedly recommend it.
Well it's quite easy at the moment and they are trying to make A10 harder, act 4 isn't in yet either.
It's not a PvP game where you expect a 50% winrate when appropriately bracketed. In STS1 I think only 1 unwinnable seed was ever found.
I am excited to have a game I will be playing in 5 years and still discovering new things about.
Can they make it easier instead
You can play on A0 through to A9 :) or with custom runs.
It's nice to have high difficulties that take hundreds or thousands of hours to master. It's very rare to have games that hold up after years of play.
Oh we have not reached A10 w anyone, weve been playing just those ascensions anyway
maybe we will try a custom run, the unpredictability is a part of the fun tho but its been too unpredictable for us 
tips if you want them
Don't take speculative card, take cards that solve a problem your deck currently has. Exception: hail marys when you have no hopeDon't build a deck that counts on not facing a certain boss.
Strikes are a terrible card, an early priority is to make sure you aren't playing them. Removing them, diluting them, or adding card draw help do that.
Don't add card draw if you have nothing good to draw.
Don't add 3 cost powers/cards unless you have a way to play them (e.g. hold them till the right turn, extra energy and the card in the same hand, zero cost block, or the card solves a turn)
When routing, mentally add up how much HP you expect to lose. Obviously don't take a path where it's more than your total. Try leave ways to choose not to take a dangerous path if things go bad but try fight 3 elites if you can do it safely.
You get 3 easy halway fights act 1, 2 in act 2 and 3. After that they get spicey, keep that in mind.
Skip is often the best card in the card reward screen, unless a card does something don't add it. Be cautious about taking attack commons after solving the "have stuff that isn't strikes to play" problem
All of those have caveats, and I lose slightly less than half the runs I play so you know... Just that when I see people struggling they're often making mistakes like that because they think in terms of "good cards" and "bad cards". So a "good card" like idk void form comes up and they pick it but that just made the "I can't block enough and take a lot of chip damage" problem they're facing worse (at least for the first deck cycle).
That said there are a few cards where you almost can't have enough copies like footwork. As a win condition for any character is "play 10 footworks and then each defend will fullblock and I can do whatever I want" so keep an eye out for those :p
there's asterisks on that unwinnable seed like not starting with neow's lament and not doing glitches to get extra floors. we wouldn't call a mario level unbeatable if you had to do a wall clip, everybody would just do the wall clip.
I think it’s fair to call it unbeatable if it requires a glitch to get through. There’s actually a situation like your example in the C64 RoboCop game where you can’t finish a level normally, but it’s possible to glitch through a wall.
Of course, in that case you can’t progress because that version of the game is literally not finished.
Well, you don't assume an average seed requires any glitches etc.
Generally the game was extremely well balanced for challenging but winnable play. Although sometimes finding those lines can be very hard, I don't miss gremlin nob lol that was a very frustrating enemy to have shaping early deck building.