It's like they wanted to tell a classic Harem/Ecchi story, but wanted to cut out all the "fluff" and condense it into one episode. They succeeded on that front, but in so doing they also cut out anything close to meaningful progression/development or reasons to like/relate with the characters.
Story - There is none. There is no plot. There is no story structure here. No problem to overcome, no emotional pull, and most certainly no closure. This isn't anything more than a string of ecchi scenes thrown together.
Animation - Actually suprisingly decent. The art is beautiful in a lot of ways, and there's definitely attention to detail in the characters' movements. Unfotunately the primary reason to watch this (breasts) seem to have gotten the short-end of the metaphorical talent stick; they are misshapen or mis-angled in a good portion of the ecchi scenes, which makes them stand out against the otherwise good-looking art.
Sound - Pretty standard. Nothing to write home about, but also nothing upsetting. Voice Acting is pretty well done, too.
Characters - Only a slight bit better than the story. That is to say, they *are* characters and have character traits that uniquely identify them from each other, as well as distinct visual designs. That's about it, though. You have your standard cardboard-cutout MC who for some reason continually tries to reject the girls' advances, rendering his character as nothing but a string of "No"s and "Sorry"s. You then have 4 different takes on the "Girl falls for MC" trope, all falling somewhere in the Tsundere - Yandere spectrum ranging from "Hold me or else" to "I'll straight up kill you".
Overall - A really disappointingly mediocre anime. Nothing of substance to develop on, which itself isn't necessarily a bad thing - sometimes you just want good visuals without following a plot - but it suffers from a lack of follow-through on those visuals. There's really no reason to watch this unless you're some kind of completionist that wants to watch every anime tagged with "Borderline H".