Storyline: Underdeveloped. It feels more like I was shoved in the middle of a random story, and not everything makes a lot of sense to be frank. It is also incredibly short and I feel it needs more options, as that is a key part of what makes dating sims successful.
Graphics: They aren't fantastic. Maybe you should have started with a pencil sketch, and you don't necessarily need a tablet to create good graphics. There are lots of artists who create amazing stuff without using them, I just think you need to practice more.
Writing: There are lots of grammatical errors, which may not bother some people but I find that it looks slightly unprofessional. Spell check is pretty easy to use, and if English isn't your first language I'm sure there are lots of people who would be willing to look over the writing and help correct it.
I've never felt that newgrounds was a place to upload "experiments" or first games. This isn't the place for it. Newgrounds is where you showcase your best stuff, and since it's so open anyone can post their creations regardless of whether they work from some big gaming company or from their mother's basement. My word of advice, take your time before you upload something!