As cute as it looks, i cannot give it anything more than two, however much i want to give more.
First of all, you need an actual Gameboy or Gameboy Colour emulator to play it, which isn't an issue for me since i have them at the ready but many people don't want to even try them out, so you are warned.
Second, the entire thing lasts for 10 minutes at most, it's one short scene and you barely have time to say two words to the girl. If this was longer and had some build up i would be much more lenient to it but it's essentially one scene with 3 small irrelevant choices. You come in, bang a cute musical goat girl, the end.
Girl design is admittedly absolutely adorable and if it was an hour-two hours small VN about how they met and how it went, it would be geniunely awesome. Making it as an actual Gameboy game is a unique and bold choice and it's definitely an aesthetic that works, but it's simply way too little and simple.
It's a good framework for an idea, just really need some meat on it.