For M… I played through again last night for the R/A triangle and got a different, and very cool, ending for M, where he somehow ended up with V? Or maybe I was half asleep and imagining it. I think I dreamed about these characters last night!
I have only played three routes so far: A, R, and A/R (that order since my MC flirted with A first–I restarted after flirting with R first then going to A because my MC felt like shit!).
I think A’s romance was handled really well–he’s the ice king, but there’s some fire under there and it’s fun to poke and prod it to get it to flare. 
The piano scene was superb! And I think the build-up to it was perfect (btw, my MC on his path alone liked telling him she’s tempted to run away to see how he “punishes” her… and is willing to risk life and limb to provoke him into it, please give us that option in book 2 and the ability to make clear it’s just a provocation so A’s head won’t explode).
R’s romance… well, like I said in the other thread, it wasn’t as annoying as I’d feared. I mean, I get him–he doesn’t know wtf is going on, doesn’t understand these “feelings” and urges that are popping up, and–most of all–can’t fathom anyone actually liking him in that way, so the thought of doing something about it is foreign to him. Though it’s frustrating to read, it mostly works in paths where the MC is shy or equally as stubborn about feelings. It’d be nice to see a few options where an MC could have the same attitude as R, too, where they’re in complete disbelief when R actually (hopefully?) is willing to do something about it. For a forward MC? The romance is non-existent, really, and borders on creepy because it gives off the feeling of the MC chasing someone not only disinterested, but completely disgusted by the forwardness. Just my opinion, though.
For the triangle? Again, A’s path is unarguably a “romance”. R’s path is actually, in some respects, more obvious, because there’s some jealousy popping up from him (even if he doesn’t quite get that it’s jealousy or where the anger is coming from). Yet, he’s still not willing to shit or get off the pot, which makes it frustrating. I’m really curious to see how that plays out in book 2–if he just continually sits on the sidelines pouting or if he’s willing to do something to show the MC he really is interested (and that last part also goes for his solo path).
I can’t answer for the other paths, but might make up some characters to try with them, just to be able to provide some feedback.
Having said all that, please don’t be discouraged over feedback complaining about a lack of romance. This is a series, so you basically used book 1 as a build-up to what’s coming later, correct? There’s another series out that is completely romance-focused and her first book had no more “romance” than TSS. In fact, you gave us a hell of a lot more, IMO, since you gave us some real progress with A (and M and G, had I to bet) before the end of the game.
Of course, each person’s definition of “romance” is different–I don’t consider longing looks and endless, fruitless flirting to be romance (and I get bored quickly with that crap), but some people do. IMO, you gave us a lot more than that.
It looks like Slenderman’s family reunion.
so in short, yes! I imagine you’ll have to choose between them eventually, though.
but to be clear, 
