Nice visual novel (playing it takes about 20-30 minutes): It is a cute, gay romance, a story about getting to know somebody and sharing your interests, insecurities and feelings. The game manages to characterize its protagonists effectively and make us sympathize with them. Given the limited "space", this is done very well. Of course, there is no room for great psychological complexity, but the characters are accessible and relatable. I also liked the illustrations and music.
VERY MILD SPOILERS (and some rambling):
There are only a handful of choices which do not affect the storyline, but lead to different bits of conversation. I was a bit suprised by the gender assumption that seemed to come out of nowhere. And since I had no idea how the title "Serre" relates to the contents of the game, I had to look up what it might mean - apparently it's French for a 'greenhouse'. Mystery solved! :)