A near-constant rollercoaster ride of action, misery and instantly-regretted decisions
Honestly, I haven't played a lot of adventure games. The only one I recall in recent time was another Telltale game (the similarly episodic but otherwise incomparable Back to the Future game). But I suspect even if I had been keeping up and had a proper benchmark for comparison I'd still be rating this five stars.
The less said and spoilt about the actual plot, the better. But I think the biggest (and possibly most misguided) compliment I can give it is this: I have no interest in playing it again any time soon. Yes, it's an adventure game with dozens of choices big and small. Yes, I could go back and make different choices or try to avoid the worst outcomes or even just find out whether the player deaths ever become particularly gory. But I picked my story, I was emotionally invested and then my story ended. Going back to change things just because I can doesn't feel like a good enough reason to lessen the 'realness' of the one I experienced. After all, it's not like there's a magical perfect ending. (Having said that, I certainly will eventually. Doing and saying nothing is a surprisingly available option, and I wonder how well the game handles a player who knows the plot twists and actively tries to subvert them.)
The gameplay itself is mostly a background to the story being told, and it stays out of the way appropriately. Your inventory is rarely more than two items, and the game only lets you use them where they're relevant. Quicktime events fit into the action, and weren't that difficult or complex (and ones that must be failed don't keep you trying for too long). Supplies and ammo are never dealt with directly, and overall difficulty of action scenes is nothing compared to the moral quandaries you'll face. Limited timers during conversations keep the stress up, but are slow enough to let you read the options, and on the rare occasion the response isn't identical to the text you selected it always matches the tone. On the other hand... The game has a few cheap 'scares', a few scenes/puzzles are slightly too long (especially when the solution is obvious but how to perform it isn't) and some of the camera angles aren't quite perfect, but they're exceptions and even then not blatant enough to ruin suspension of disbelief for me.
I didn't exactly rush through it - I averaged at least two hours per episode and a day or two between, though I'm sure it would be a lot quicker on replays or when not exploring every crevice. You wouldn't want to play it all at once in any case - savour it, "the journey there is half the fun" and all that. (Speaking of episodes, my score is for the whole season since I can't be bothered writing five reviews; episode 5 is a great ending but not the best individual episode, deserving 'only' four stars.) My version had a few issues - apparently I avoided the save-loss bug through luck and impatience, and the game wouldn't even start if my gamepad was plugged in, but they didn't come close to bringing the score down a notch when compared to the rest of the game.
Everything I haven't mentioned: the graphical style is a wonderful fit and surprisingly good-looking; voice-acting is routinely amazing; the characters themselves - which I wish I could talk about if I knew how to do it without giving anything away - are relatable or at least believable. You'll laugh, you'll cry, you'll feel dead inside. Go play it.
Oh, and there's a cutscene after the final credits. It's not vital but it's there. Just letting you know.