I liked the bold, colorful style of the sprites! The one thing I would suggest is to darken the background just a bit or desaturate it so the sprites stand out a bit more. The bright green appears more vivid than the blue or red of the sprites, and tends to draw your focus away.
To see what I mean, you can look at your primary thumbnail compared to the screenshots below it. In the project thumbnail, the sprites are much easier to see against the darker background. The only thing that blends in are their faces a bit. In the screenshots though, I notice the tree in the background first before I focus on the sprites.
I was a little confused trying to follow the narrative of the altercation. I am glad you included one though, as this is something virtually all relationships have at some point. In the ten entries I've read thus far, I don't think I've come across any others that have included major conflict and resolution between those two characters.