Wonderful art style, animation, and environmental storytelling! Reminds me of the classic "Another World". Definitely a lot of potential here, it would be great to see the worldbuilding and plot developed further along with more gameplay content.
As for the gameplay, it felt like a comfortable balance between action and puzzle elements. The world was so interesting I would've liked more opportunities for exploration and side paths, but I understand there's limited space for that in a demo/prototype.
The weakest aspect was the platforming mechanics, which felt pretty stiff and clunky at times. Sequences like sliding down the walls with traps, or jumping on platforms over lava, felt more tedious than fun. I think you might be able to tune the controls a little for smoother movement, but you could also just avoid level designs involving precise platforming as that doesn't seem to be what the game is really "about" anyway.