incredible visuals! Controls feel nice! Such a great little game. Played it on my GBA last night. Really enjoyed it. I totally agree with ChunkySteveo below. If you're finished developing this, I'd just call it Bark Sequelo and leave the Demo off the title. You might call out that it's a short game, but he's absolutely right. This is more feature-full than many other GB-esque games on itch.
That being said, I would love to see a longer version of this game. If you're interested in working that way, you could also leave this as the demo and keep developing a longer-play game to sell. Or just leave it as-is! Haha, it's fantastic!
Whatever you decide to do, props on an incredible project! I love it!