Quick question: Why do I have these images in my game files?

I got there to see if I could hack the game to restore the first-time menus (if anyone knows, please do tell me) and I found them. I don't even know how they got there or what they're for.

Teaser. Song by Youtube Fazy, I believe.

I've been working on something. Something big. Something, I hope, you will find

fascinating.

Truly,

fascinating...

So...

It appears we're early, huh...

...

...wait.

...Early?

Early to what...?

Frisk

A taste of what's to come. It ain't much, but I'm doin' my best from over here!

he secretly thinks it's cute

(For anyone who might want them, here are the sprites of the Vessel from my last game. [Fair warning! The base sprites for this were those of aamakuruu, y'know, the edgy Kris? All I did was to resprite them, since I'm terrible at drawing]).

It is with great pleasure that I announce that I have been working on a new Deltarune fangame. I was not alone this time, however, for I had the great help of @Chuckles02 . As for what the game is about... I'll give you a hint. It is pretty hard, though.

Undertale, but nothing's wrong.

* You looked into the mirror.

* ...

* It's only you.