Hatsusaku is Yuu Niijima's masterpiece. In the West we have fragmentary knowledge of his work, but Hatsusaku is way better and focused, and hits harder than the likes of Majo Koi Nikki ("The witch's diary").
Yuu has notably written for Key, but his input was reduced to like one route a game. In Hatsusaku, he has the chance to shine. Hatsusaku shines for the melancholic, nostalgic winter ambience (play it and you'll see), but it's festooned everywhere with comedy (sometimes, even often, of sexual nature). If I have to mention a poor spot, it's the heroines. They're not that attractive, and instead serve to move the plot forward in a satisfying way. With everything you piece together during the 30-something hour gameplay, you get a full picture of the city of Uchida-Kawabe and its atmosphere.
I don't know why, but winter VNs have the potential to be the most touching, I don't know what the season has but it's very emotional. In the end, spring comes for everyone. Or that's what I like to think.