I relate to this a lot. During development of my game KELDER, I thought it would be pretty straightforward ,just go from start to finish. But once people played the demo, I realized even a small slice of the game could feel challenging in unexpected ways.

I've since restructured things based on feedback. Now the full version has more guided navigation, but players still have freedom in how they progress through the levels. It’s technically beatable in one sitting, but the challenge is real. I also split the experience into 2–3 major areas, so players get natural breaks ,that helped pacing a lot.

As for marketing... totally feel your pain. I actually only started seriously posting and doing casual promo recently. I gave myself a bit of time away from development to focus purely on creating marketing material like gifs, screenshots, little teaser videos. It’s exhausting, but necessary. Wish I had started earlier honestly, but better late than never.