A really interesting sentimental piece from a non-human perspective. A world without you is a minimalist poetry game executing on both aspects in equal measure, the game shifts between a top-down exploration game to a poem.
It makes a lot of sense you went for minimalism to both cement the vocabulary of the game in more interactive means (top down movement) and to allow the player's imagination wander to explore the suggested visuals.
Your design language was very clear, and tutorialized well, such as the flies being a small flavorful non-gameplay progressing interaction which then allows for catching hearts or stars to make sense.
The mural sections such as the Rose(in the ending) and the Hearts(with Maria), as well as the seasons section were interesting and served as the more poem parts of the game, contrasting it with the more faery-tale aspects of asking every creature in the house and garden.
I liked that you broke the top-down convention of what up means, when you allow the player to climb up a ladder to touch the stars. The same way poetry creates meaning by juxtaposing multiple interpretations- in your game walking can mean flying, can mean dying.
I like that I planted the rose in the stars, where Maria and maybe the kitten is.
Because you go in this format of exploring it through poetry time is allowed to shift. This game is only perceived to move forward when the kitten thinks of Maria. The seasons shifting is a good poetry trope to borrow for this game.
Good job :>