What a cute and simple trick-or-treating game!
Despite the simplicity - there is clear strategic design at play: even though the character designs are simple, all of them have little identifiable differences down to the eye colours and shoes, so you'll always be able to identify Suika no matter which costume she wears.
It's a game with not a lot to it, but that's its strongest point: it seeks to accomplish a simple objective and succeeds. And the art style is very cute!