#not underswap

Toriel is a bit less of a pushover then Asgore and was considered the brains between the two, so she wouldn't let Undyne be the Royal Guard Captain or Alphys be the Head Scientist, due to the former's temper and the latter's nervousness...

Instead, the Captain and Head Scientist would be different and more professional people...

And Papyrus is actually part of the Royal Guard, but he's in the lowest rank...

Undyne is also still in the Royal Guard, but she's only a rank or two above Papyrus, while Alphys is an alchemist instead of a scientist and while she's technically not part of the Royal Guard, she forms a trio team with Papyrus and Undyne to try capturing (and possibly destroying) a human together.

The robot that later tries to attack Frisk isn't Mettaton's ghost, it's instead the Mad Dummy's angry spirit. (But the robot body helps calm his temper somewhat.)

Mettaton is with Napstablook and they formed a band.

Sans is weakened, has almost lost all hope and stays in bed most of the time; he's on the brink of falling down.

The amalgamates don't exist in this story, instead Frisk would find the human souls in the True Lab.

Gaster (who's trapped in the Void) is the one that created Flowey for some reason.

Flowey is basically the same, except he's somewhat more patient.

Flowey tricks Asgore into thinking that he a friendly flower and tricks Frisk as well.

Asgore makes Flowey promise to watch over and protect Frisk, if the child ever leaves the Ruins.

Flowey becomes Frisk's partner and he tries encouraging Frisk to destroy the kingdom and find the other humans souls.

After a reset and learning of Flowey's true colors, Flowey tells Frisk that if the child tries to leave Flowey, then Flowey will tie Frisk up in vines and tell the Royal Guard exactly where Frisk is.

So, Frisk is forced to let Flowey stay a partner.

Asgore would still try to battle Frisk, but he would desperately beg Frisk to stay and at the end of the fight, he would burst into tears and apologize to Frisk.