Really cute artwork and good animations in the side scroller sections. I liked the concept of the game but I wish there was a bit more to it. Maybe the overworld can have metroidvania style unlocks that you get by completing the side scrollers? Or maybe you find one ingredient at a time and bring it home and you get something to unlock the next section.
I wasn't able to find all the ingredients and some of the environment cues were hard to read. I had to figure it out by trial and error. Some audio would have really helped as well. There are free sound effect generators online, check some out - they would be perfect for this style of game.
Also love that you used Rust. I'm a rust enthusiast myself and would like to write more Rust since I don't really write it that much outside of little hobby projects here and there. Bonus rating point from me for your choice of language haha!