Congratulations on your first game! Really interesting game and story! Your characters were really well developed and their personalities really showed through their dialogue.
Here are some tips for next time you make a narrative game or do a game jam:
Create some more branches in your narrative, the more choices you have the more the player is engaged in the story. It also makes them feel like their choices matter (even if they don't ;) )
Team up with people who can make original artwork for your project, even if they aren't as good. Original content is always better when jamming. Working with others also helps create a better tested game, giving feedback on each others work.