(Playing devil’s advocate here for a bit.)
Write better short stories. I see short stories (or short IFs) more as a different format of stories that work amazingly well for some concepts, but not at all for others.
Yes, a lot of people who leave feedback about the length of games do so because they were expecting more content, read through it once and never saw the other branches, etc, but it can also be caused by the length of the game making the events that happen feel rushed or making the game itself feel incomplete or lacking what feels like crucial choices to the people reading it.
Tldr:
If you’re writing a short game:
- Make sure your concept fits the format.
- Make sure each word you write counts. No filler words or segments.
- Make sure you’ve wrapped up at least the main plot arches at the end of it, and preferably all the minor ones too.
- Ask for feedback from your (beta) readers specifically about having gotten all the choice options in the game that they were expecting.
(Check out the Feedback Assist thread. We have feedback people.)