No one should ever compare this manga with anime, since anime has NOTHING to do with the manga or the game itself. Mostly character's physical outlook and the names are similar in the anime, but that is generally it.
Anime is totally different thus is a Kimikiss Alternative rather than Kimikiss as such. So one should forget about comparing it with manga as it makes no sense whatsoever.
The manga has each volume dedicated to each heroine separately, which it makes more sense considering it was a game with all interactions and possible choices between heroines.
It makes more sense than anime, where they try to force it all into a singular plotline by adding more idiotic main male leads that look more like a siblings of the main character and have pathetic personality (or lack of it).
In this manga there wil be no real twist just straight forward romance, which will probably make look characters a little bit dumb. Yet I think its still much better choice than in anime.
This way each heroine will get her own time, and will end up with main hero. It will reset by the beginning of each new volume as it will switch to completely new heroine.
Yes, mangas plot is simple and characters are dumb, but it actually can be a great relief from those annoying plot twists that look forced and could be guessed miles ahead. Its your straightforward romance where heroine interacts with the main character and the end up being in love. I find it to be a pleasant break from your typical mangas or animes (Like Kimikiss alternative for example).