I gave it a shot, and... well, it's certainly sparse content-wise. I think the thing that annoyed me the most—and something I hope is rectified as the game gets more fleshed out—is having to "take a nap" every day just to progress the story; I would definitely hope for a more free-form game where you could interact with the other Gems in the same time frame instead of it being "episodic", for lack of a better term (i.e.: one character at a time until the next chapter).
Keep in mind this next bit is just my opinion, but... I think Garnet is the worst choice for fleshing out the beginning of the game for a number of reasons, most of them relating partially to show canon. Or maybe it's just my sneaking suspicion that these characters aren't exactly written well (spelling and grammatical errors aside). First and foremost, she's the fusion of Ruby and Sapphire—she's basically a lesbian. Plus she's the most serious, placid and down-to-earth character in the show, so these kinds of things probably wouldn't interest her much. (Yeah, I know. Look at me, critiquing the plot in a porn game.) Finally, I feel like the basic plot was a bit... contrived and somewhat rushed. Normally, I steer clear of visual novels and go for games with more... well, "gameplay" like platformers or the occasional RPG for exactly these reasons—character interactions in VNs rarely seem natural to me—but I tried it out regardless because the subject matter interested me.
If it was my call, I probably would've made Pearl the first character. She would have a closer personal attachment to Steven since she not only worked under Rose Quartz but also... well, if you watch the show, you know by now. (No spoilers.) She also has more of an innate curiosity towards humans, and she fits the stereotype of a more doting motherly figure to Steven. Second would probably be Amethyst, just because she's more laid-back and prefers spending time around other people; Garnet's not really a sociable character, and her dialogue is a bit stilted even in the show, whereas with the other two, you would probably have an easier time writing them in a more casual setting.
It's got a long way to go, but there's a glimmer of something there. It just needs refinement.
