How to make a choice game...

How do I make a game of multiple choices? (Choices that change the game).
What tips can I follow?

I wanted to do in the style of: Seen (Android), Emily is Away (Steam).

And how can I follow the above styles?

Thx.

Here’s a tip, go read some tutorials on how to do a visual novel game in unity. Here is one I located after a google search:
Visual Novel Tutorial

Here is a framework called fungus that facilitates interactive stories in Unity:
Fungus

If by style you meant art style, I would recommend reading tutorials on creating pixel art. Here is a link to a website that has 30 tutorials for pixel art:
Pixel Art Tutorials