DISCLAIMER: This game is not for everyone. Before starting the game, read the warnings clearly as well as the tags associated on the Steam page. Speaking from experience, it can mess with your mind.
If you are a fan of anime, manga, visual novels, or anything related, this is a MUST play. The mind behind this game, Dan Salvato, crafted a story that soundly criticizes anime/dating simulation tropes, creates characters that have heart-wrenching depth, and holds enough secrets to give the game lasting appeal in one three hour package.
It is also packed with decent to fantastic visuals. Thanks to the work of the character artist Satchely, each girl has a distinct appearance that clearly establishes certain personality traits as well as subtly suggesting their importance to the story. These characters interact with each other over detailed backgrounds provided by the artist Velinquent, such as classrooms with walls covered in high school club promotions and calendars. Both of these visual elements compose scenarios not unlike traditional slice-of-life anime, which complements the overall story very well.
The fanbase is also quite active even now. When you wrap up the story, you can head over to the DDLC subreddit where fans share art and mods that can scratch almost any itch you have involving this game. The passion that the fandom has for this game manifests in extra content that you can explore to your hearts content. I recommend "Doki Doki Outcast." They can be toxic sometimes, but not much more than any other fanbase (not even close to Star Wars).
It isn't perfect, as one character in particular does not have the same level of depth as the others, a fault acknowledged by Salvato himself. There may be other problems alongside this one, but I fail to see them.
This may be one of my favorite video games and it barely counts as one. I consider this game to be more than some viral trend, but a masterpiece. That's just my opinion. If you haven't played it yet, give it a shot, especially if you somehow haven't been spoiled. This is a game that hits hardest when you aren't expecting it. Just be sure you can mentally handle the hit.