They're strong enemies with good buffs and debuffs and some of them summon minions, but for the most part they don't shut down certain playstyles or respond to the types of effects in your deck. The bosses of the first 2 areas are a stiff challenge, but can be beaten by a variety of decks.

Speaking of the third and final boss, I think 2 of the game's 3 final bosses are needlessly punitive of certain deck styles.

You can often survive to the end of the third area just with a well-drafted deck of decent cards and some careful play, but if your deck doesn't have some super disgusting combo effects between its cards and relics, usually the boss of the third and final area will just crush you.

I just sit there, skipping a lot of mediocre commons, waiting for anything that is actually worth shaping my deck around, and sometimes it never comes. Maybe every rare I find is just kind of generally good (maybe an Offering or Adrenaline which both draw cards and give you mana once per battle but are hardly a theme, etc.), so I'm never in a position to force my deck into a defensive style, or a poison style, or a discard style, or whatever the case may be. Maybe I found a sweet relic early in the run, but of all of the card choices I'm given, I find none of the uncommons or rares that actually capitalize on that relic, so it wastes away in my inventory, contributing almost nothing. This problem can afflict many roguelikes, where sometimes all the random stuff you find just doesn't become greater than the sum of its parts.

In bad runs that ultimately fail, you either find this defining rare card or relic in the 3rd area when it's too late to shape your deck around it, or you just never find one at all. Great runs often result form your finding a particularly good rare or relic in the first area which then shapes your deck building as you. Due to the game's randomness, there are runs where even well into the 2nd area, my deck has no build-around-me rare or relic, so my deck-building is directionless and has no main synergy to take advantage of.That being said, I have 2 major complaints after my time with the game so far. I've had a great time drafting different decks with it, and hope to see the game continue to improve in the future. It strikes me as a 'in the right place, at the right time' sort of thing that just as people were wrapping up Hearthstone's Dungeon Run mode and wishing for more content, this new game appeared to fill that vacuum. I noticed a trend among several Hearthstone streamers where they all got interested in Slay the Spire after burning out on Hearthstone a bit in the past few months. Its owes a lot to Hearthstone in more ways than one: it has some UI similarities, the relative simplicity of card effects is more comparable to Hearthstone than to something like Magic, and Slay the Spire entered Early Access right around the time that the Hearthstone world was abuzz with the Dungeon Run mode, a similar roguelite mode about drafting cards and powering up your deck with passive effects.

Slay the Spire occupies an interesting position for me.

My spire