First of all, congrats on your first game! It's a small step in your journey, but it's one of the most important!
I liked the mirroring mechanic, and the different worlds, forcing the player to navigate two characters at once! It reminded me a lot of Fireboy and Watergirl!
The potion throwing mechanic seems a bit buggy, as others have said, being unable to throw the bottle, or damage the spider?
But overall, I like the art style and the movement! You did a great job! Keep on making!