Good family job. Nice atmosphere with the sound and graphics. I am curious what these light orbs floating around are, and I was curious to walk and discover the area. I was wondering what the building far away was. I liked finding stuff around, the feeling of discovery is there.
Is there a story behind this scenery? I am curious. Regarding the secrets, I am not really sure what I was picking up. At some point I picked up a sort of pillar, when I thought I was seeing a note on it.
As you said in your game page, the music isn't looping, but that's just a minor technical thing.
I found the character movement a bit slippery, even more when on top of objects like the crates. It feels like the character is sliding.
For your future project, the inventory will be a great addition. I would personally like to know more about the story you are trying to tell, and it would be nice to have that through the items we pick up. Maybe even just being able to look at them closely in the inventory to understand better what it is, or have a small textual description, to still keep the mystery.