Why hello there!
I just took a quick look at your comic for the moment, but I feel like I should start by saying: Don't change your story just to attract an audience. Love what you write. Write for you. Write something that you would enjoy reading. At least then, it will always be fresh and exciting to you.
Writing for others is a massive waste of time because it is impossible to please everyone. As well, there's no way to know what people will actually want. Having dynamic, relatable characters is really the only way to assure success.
That being said, I feel my advice to you is actually art based. I'd recommend working on your colouring and line work. Try to add an extra layer of polish to your art. Colour is what draws people in. It's the first thing they see. Add some shades, colour dimension, etc.
This channel has some great colouring advice: