The first episode reader has for free (no passes needed) - so it is essential he will like the story enough to try 2 chapter and spend passes on it. If you do not impress the reader in 1 chapter he might simply leave and never try the next chapters.
Therefore is 1 episode more important than many think.
And what is reader looking for:
1) Exitement - mo matter how, it is essential that the reader will be thanks to the 1 chapter interested in the story. So it should not be boring, it should already have signs of what will be probably set story about atc. With this goes things like good dialogues 3D characters, good writing skills and good directing - you are simply showing the quality reader can expect in upcoming chapters and showing what the story might be about leaving reader curiouse what will happen next…
2) Lenght - the length of the episode is not about the number of lines but about the reading time. You can have CC of multiple characters easily making your story to have 10 000 lines and still if a reader doesn’t want to customize he can get over this within a few taps. So what is the best you can do - take a stopwatch (there are many online - and start reading your story and measure the time. Try to really read it even you know the sentences. This way you will easily get your episode reading time.
There are many poles about prefers length of an episode - from my research 10-20 minutes of reading time is what the reader expects most. Ideal is 10-15 - this is liked by most readers of episode. If your reading time is much shorter than 10 minutes in 1 episode the result will be that some of your first-time reader will think all your episodes are most likely way too short and will not be interested in reading your story - simply he can spend only 4 passes and most people will not do it thinking they will get only 5 minutes of reading per pass and than have to wait for several hours for a new one.
3) Choices and CC - most readers want the interactivity. some writers do not use it but they have to count with that there are readers who from principle do not read stories if there is no CC. The same goes for choices. If you plant to have CC in your story put it in 1 chapter - at last CC of the main character. If you plan to use choices in your story show it to the reader in the 1 chapter too - if he will see choices in 1 chapter he will know you are offering an interactive story
4) extras - if you are a skilled director familiar with all kinds of animating effect with overlays or with minigames etc. - it is good to use somehow your skills in 1 chapter so the reader will know he can expect some amazing directing. If the minigame does not fit the 1 chapter some really cool intro is enough.