Very good. Can't believe this was your first ever game jam! The gameplay is simple but the basic mechanic and possibility of choosing different branching paths through the levels makes it feel bigger than it is and adds a lot of replay value. The music is excellent, and I love the way you used the minimal 1-bit assets to create a real sense of place. Nice chilled out, casual vibe. Really well done!
My one criticism might be that the controls felt a little floaty, especially the gravity-defying jumps. But that is a personal preference.