Comment by AuryGlenz

I’m guessing that’s built on Stable Diffusion/Flux just as RetroDiffusion is. That would mean it’s not directly pixel art and needs to be downscaled after the fact. The results can still be pretty great but it’s not super ideal.

Training a small (64x64 or the like) pixel based model instead of something that relies on a VAE may in fact be cheaper than what’s in the OP and could probably make someone some good money besides but the lack of training data would be a huge issue.