This game is built on a strong premise, of a young man returning to a 'family' he once had. While the setting may seem cliche, and the progress relatively linear, that's standard fare for a visual novel.
The skill here is in how well the advancement has been paced, with slow-burn buildups interspersed with sudden spikes in sexual tension. Also, the variety of characters and the different approaches to each of them keep things interesting.
Sometimes it seems like the story takes a back seat to the sexual schemes, but it develops in the background and adds an extra layer of intrigue to the proceedings.
Of course, a 5-star implies perfection, which is hard to claim for an unfinished game, but in the context of the rest of the games here, WTHI makes a strong case to take full marks.