The part that stuck out to me most previously was the fact that it makes excellent use of the VN Media form to tell the story and present gameplay. There's a lot of choice and your decisions unlock further options in further playthroughs, even if it sometimes get a bit much to go hunting for unlocking different endings. The only thing I missed in this was a clear way to see what route you're on, as it's tempting to mix and match and end up with one without realizing it the first time through.

The excellent use of the VN media form was the one thing that stuck out to me until this update (V20) which tied everything together in a much better way for me.

The reason that was the one thing that stuck out, rather than the story or setting is most likely due to the game feeling as "three games".
On the surface this game simply looks like it was made to get people off. Rather, it probably is. And yes, it does that well. 
However, at the same time it's bunched in with a whole lot of comedy and some interesting world building and heartfelt stories. They're just behind the surface. 

It's easy to fall prey to prejudice and think that horny is all that there is to the game while that content is not bad, there's so much more to it. This is where a few of my friends have gotten stuck and didn't really want to continue, despite the quality of the content. To me, that's unlucky, because somehow those moments also help build the entire world and story.

In every moment there's some kind of character or worldbuilding. It's often in silly things, such as looking at Rune's balls 'to see if there's mana storied in them' introducing mana. There's the balls, which I find hilarious, but some of my friends just couldn't get past, at the same time it makes your mind go 'Canine mana? Human mana? What's the difference?' These little snippets of information makes the world feel more real and thought out. 
Further, it's all quite grounded. It's things that make sense, such as canine mana having canine properties. Pack mentality, improved smell and so on. It helps make the world more relatable.

Further on, every character seems to have an interesting backstory of their own, which ties in with all the worldbuilding and makes you ask questions such as 'who is in charge? where are they from?' It makes the characters feel more real, on top of helping introduce their goals and personalities, wishes and wants. The part that really makes it click for me is the fact that the world seems to have impacted every character.  We're told this epic story, and the characters are actually a part of it. 
The exception for me here would be Alon, I love the character and he has fun moments but for whatever reason he seems like bit of an afterthought. He sticks out just a tad too much, despite hinting at being a villain of sorts.

Moving on, it's the fact that the world building actually delivers which makes it a pleasure to play the game. What has me focusing on that so much is that there are more than a few (great) stories out there which have a lot of the same qualities when it comes to characters and worlds as Shelter does, but they never deliver. They have a great world and interesting characters, but they're never tied together. There's a world, and a story, and characters. And mostly two are tied together, but almost never all three. Shelter ties all three together, and it does it well. Shelter doesn't introduce Chekov's gun (bomb) and never have it go off. That's what truly makes it stand out.

The bath sequence shifts the tone from the "horny silly" and reaches a breaking point where it tills over to storytelling. It suddenly drops most of the goofy parts and forces you into the present, with the attack on shelter. 

All the hints and backstory we've gotten so far click, and Burry and Luke are all tied into it. We learn more about Skies ablaze, and what it all entails. Pack mentality and the differences between races is expanded on and further tied in with Luke, who as a human somehow is more relatable which really makes the reader fall into the role as Luke.

Now, Burry's route is a dark story filled with action scenes (which are excellently written and presented. These are difficult things to write in text or VN format, in my opinion). There are no stops. It is a loredump built on information we've been given before, so it doesn't feel slow to read. It ends up being puzzle pieces falling in place.

Somehow, I felt like I was missing a few pieces with how Burry felt within, rather than "at peace". It still tied together nicely, but with how good some other descriptions are it felt a little barren.

It was heartfelt, as promised by the question in the bath, and it went through a lot of different emotions. Somehow it turned into feeling more like reading a book than "watching a scene" at that point. I was missing a bit of interaction with Burry's brothers and despite it being such an important part of the story, we only got the tail (heh) end of it. It didn't hurt the story, but that's where I would have liked to have even more added in. 

Other than that, I loved the introduction of the wolven rule and the contrast between Burry's backstory, and how most common dogs probably live. It made my mind wander.

Now,  on to Luke.

We get to follow Luke, and in the story somehow all the options the player gets to pick somehow feels like choices Luke would make. There's no "wrong" or weird choice. We still get to make them, and they make a difference in outcome, but they're all choices I can see Luke making. 

Luke feels clumsy when relating himself to his friends, and relates it to being human and not canine. For a human, he's not clumsy at all. Instead he's athletic and agile. But he still feels opposite, it leads into philosophical questions which the story touches on about if it's the environment he's in, or just birth, or if it's all bullshit . I loved it, but it's a stark contrast to expectations going into the story with goofy and horny actions. 

It's one of many things we see Luke internalize. We get to know how he feels, and then finally why. Eventually it all breaks down and he becomes more "human". 

All in all,  a great character with flaws and strengths, with just a dash of perspective when we get to see how the other characters view him. The outburst at the bath is definitely my favourite part of the story.

So, to finally try and summarize a little.

Shelter's strength lies in it's storytelling and world building, which ties into character building. It capitalizes well on the VN media form with flags and choices that matter. 

There is no denying the fact that it is an adult game. This is as much a strength as detriment. It can be off-putting to some people who would probably enjoy the game as much as I did, if they made it past that part.

While there are ways to avoid these segments, it's not always clear. Still, I'd highly recommend anyone to try it even if they're not into that, as the other parts are top notch as well.

On the flip side, it might also be a detriment to those who want to focus on that, as it's easy to skip the story. While in reality, it's best viewed when enjoying both. It's like softcore porn in a way, the hidden details are somehow more enticing than getting al the hardcore stuff.

Finally, the above notes make it easy to miss how individual and enjoyable all the characters are. I only have great things to say about it. They're all individual and have wide personalities and backstories. 

Don't get hung up on it being horny or serious, because it's best enjoyed as both.