questions in TS!UNDERSWAP

Hi. I was just messing around with TS!UNDERSWAP 2.0' datawin file, and found smth cursed.

What is that? Is that used for some kind of ultra-secret battle?

is there any way I can put my previous Mac save file into the new demo?

Spoilers for geno/evacuation

This is rather interesting

No photos or image because i'm lazy, but you can test it yourself

If you die to Mettacrit in Genocide the death dialogue is "perhaps with this body...i can" does this mean Mettacrit is going to posses and use Chara's body?

oh hi. is this still on?
i just had one question.
how do i get the alternate menu skin? i did once but i totally forgot how.

Do you think the characters that fake their death will be more important later on? Like Mettacrit fading away or Crossbones using a cardboard cutout of him just before you kill him? or what about the characters like Coffin K who are hiding

Is there any way to replay the game from the start of Starlight Forest (exit of Ruined Home) instead of the very beginning of the game?