Flandre's Dream. - 36000 ft deep - is an enjoyable, simple game that sometimes reminds me to a mobile game of sorts.
The story is locked behind milestones and achievements, but your objective is clear:

"Try to wake up Flandre with all your might".

To play you require energy and you only get that once per minute when not "diving" AKA playing.
You can also send Koakuma to explore in order to get new girls, items, and progress in the game, but that can take anywhere from 3 minutes to 6:40 hours IRL.

Art is cute and heartwarming, the story is also endearing and enjoyable, although somewhat confusing since it is told from various POV's. Translation is decent, definitely better than most touhou fan-games I've played recently

Overall... A very good game for the price, but nothing out of the ordinary by any means.
Don't expect top-notch quality either, since UI is very simple and somewhat cumbersome when you need to "reload" the main-screen (The girls sleeping in the room are the ones who will dive, so you need to re-roll until you get the girl you want to use or progress story-wise) but I think that could be easily fixed with a shortcut from the developers.

--- NOTE: The game was originally distributed for free as a browser game back in 2017. Can be found as "フランの夢は睡深36,000歩" Twitter: @FlandreInDream ---
Changes: basically full english, korean and chinese translation and the stability that comes from being a .exe instead of a browser game.