Look at him, so adorable! TwT
I LOVE the aesthetic for this game! Also was very fun and simple.
The downloadable file is actually a web game though? You should check if the "Kind of project" in page settings is set to "HTML" and in the downloads section pick "this game will be played in the browser". After that, below will "Embed options" section appear and you can choose to embed in page and pick window size dimensions. Also recommend checking the "Fullscreen button" in "Frame options" below.