YMMV / Storyshift

• Ensemble Dark Horse: Out of all the characters of Shift 1, Asriel and Chara are the most popular (by far) and appear in the majority of the fanarts. Probably related to the fact that they have not only taken the place of Papyrus and Sans respectively, who are already Ensemble Darkhorses themselves, but also that both of their original counterparts were already very popular. Additionally, both of them are Spared by the Adaptation here, something that many wished to see, especially in Asriel's case. Seeing Chara as an undeniably good guy (unless you mess with their family, in which case they will do like Sans and give you a bad time) definitively has a certain appeal too.
• Genius Bonus: In Shift 1, Papyrus references the nursery rhyme "As I was going to St. Ives" before stopping himself and calling it boring. Word of God confirms this, with the added layer that Papyrus doesn't appreciate puzzles with no real solutions.
• Questionable Casting: While most of the swaps are either believable or treated as better than the original, a few choices can seem rather... Odd to those outside the fandom. A prime example: Mettaton as The Fallen Child. Although later installments reveal some story changes that help to muddle things a bit. Mettaton wasn't a Fallen Child, but a monster who thought that humans were not evil and managed to convince the other monsters to give humanity a second chance. He crossed the Barrier with the help of a fallen human, but was killed, which led to the monsters feeling betrayed and the King declaring war on humanity like in the canon universe.
• The Woobie:
  • Chara in Shift 1. They share with their canon counterpart the common fan theory that they were mistreated by humans before falling in the Underground. To elaborate, as a magic user, Chara was feared and perhaps mistreated (at the very least unloved) by the other humans. So, they went to Mount Ebott to kill themselves. The monsters took them in, but Chara was so used to being unloved that they thought their kindness was fake (even their family's kindness). They tried to kill themselves a second time but, luckily, their meeting with Papyrus allowed them to snap out of it and to realize the monsters were genuinely trying to be nice to them. At least, they got their happy ending in the end. Of course, you still can take their happy ending away from them if you do the Genocide route... Or the worst Neutral Routes too (the ones during which you kill all the bosses). In these endings thanks to a mistake of identity, the surviving monsters think Chara was the one killing their kind. Everyone is against them, and whoever that could've helped clear their name or protect them (namely, their family) are dead. And the worst part? Chances are, this is a probable repeat of whatever life they had on the surface prior to falling down Mount Ebott. Depending on the ending, either Chara ends up shunned and hated by all the Underground or the monsters form something akin to a lynch mob to hunt them down.
  • Asgore in Shift 1, after it's revealed that what he did with the Amalgamates and his estrangement with Toriel made him cross the Despair Event Horizon. You wouldn't guess it when you first meet him, but he actually became suicidal and wants to give his soul to Shifty so they can use it to cross the Barrier.
  • Both of the skeleton brothers in Shift 1, now placed in the roles of Toriel and Asgore from the original, immediately fall into this thanks to that alone. In the original, the king hastily declared a war out of vengeance and fury that he later immensely regretted but had to keep going with. In the case of King Sans here, he never even wanted to declare war but was pushed to by his own subjects, and he outright tells Frisk he's as good as dead if he calls the plan off. This sent his younger sibling, Papyrus, into hiding in the Ruins, where he's incredibly lonely, and with Papyrus retaining his original personality, has a very different outlook on the monarch than the original's Toriel, desperately trying to deny to himself that his brother would ever kill a human even when he knows the truth.
  • And of course, taking the role of one of the most tragic characters of the original and being an already highly sympathetic character comes Asriel!Napstablook. What relatively little we even know of this incarnation's life takes their original suffering up to eleven - Whilst in Undertale, their cousin Mettaton more or less ended up leaving them behind for stardom, causing them to become a sad, lonely recluse - Here? Mettacrit goes to the surface with the child of curiosity's SOUL to try and reach out to humans, is murdered by them, and poor Napstablook ended up turning to dust out of sheer grief. Ouch.