THANK YOU FOR PLAYING! I'm so happy you enjoyed it! And I'm flattered you made an account just to leave a comment!
I really love writing fluffy, emotional stuff. And I had already made "Dating Start!" to fall for Sans. So I figured... I might as well give the other skelebro some love, too! (And honestly, I grew to love Papyrus more during the development!)
To get that fourth ending, you'll have to pick one choice type of each of your friends (one Alphys, one Undyne, and one Sans). It doesn't matter the order or which choice, but it MUST be one of each during your playthrough. I hope that helps!
And I'm glad to hear it! I love making visual novels. I hope to keep making more in the future. :)