Hi Tania, really gorgeous graphics !
I'm a beginner too, so my advices are maybe not the ones you should take into account, anyway, here there are :
Your game really looks good, and i wish i had half of your skills in graphics. The thing that are missing the most, aestheticaly, are animations for our little character that are relatives with the actions, and in a general sense, more feedback about our actions. The "little owl" is always facing us, and the wings effect is too short and lacks animations, it makes it seems like it's not being part of your world. On the logical aspect, i never used Unity, so i don't know how hard it would be, but the physics of our character are difficult to "read", especially after catching the "big jump" item, and furthermore if this is a game for children. And you have to find a way to make it clear what are the areas that collide and prevent us to pass through. Finally, a little instructions at the beginning to explain what are the goals would be nice too.
Despite this, i hope i've managed to explain my thoughts without hurting you, because i am not very skilled in english either...
Take it like it : if this is your first game, you did really well, and i am really impressed by what you've done, keep working on it and good job !