Really interesting idea! Art & graphics is probably the part of game development that solo devs most commonly underestimate the importance and difficulty of (well, maybe tied with marketing). For solo devs especially, it's really rare to be a strong programmer
and a strong artist. So you end up with a lot of games that are conceptually interesting but not particularly enticing to look at.
Using Stable Diffusion to get fairly high-quality art in a style you like could be a game changer for devs who can do game design, programming, marketing, etc. but just haven't spent 10 years of their life training their art skills. I guess animations / sprite sheets may be hard for Stable Diffusion, but if you can design your game around that you may be all set!
Edit: I was curious and searched "stable diffusion game graphics" and found this cool video: https://www.youtube.com/watch?v=blXnuyVgA_Y The results are great! I wonder if it can do more stylized art too like pixel art
