Not everyone likes an open end, but this is a "safe route." That way the girl they rooted for can win in the way they most desire. It's designed for readers to "choose their own endings" if you will.
Like I said: Not for everyone. Personally, I enjoyed it.
It should be a law that harem manga need a harem ending. If you do not want a harem ending then you have to make it obvious within 10 chapters of the start that one girl is the main girl and the rest are just friends.
I would say it was interesting read. Premise and characters were quite unique but author didn't do any justice to them. First 40 chapters were kind of quality work, characters were fleshed out, interactions between them were interesting. After that, half of those characters stopped existing (
Maid, grandparents were never mentioned after that, despite whole story existing because of them
), main heroines became caricatures of their previous selves (
For example childhood friend was someone who was devious yet lazy, constantly dependant on MC. After 40 chapters, she was just someone who liked MC. Basically she just watched from sidelines and thought of how she loves MC.
).
Ending wasn't really an ending.
"I won't choose any heorine"
.
I really liked art of this story.
Basically this story went from somewhat unique romantic comedy to generic one (completely generic, with nothing special about it). Yet it was enjoyable. So I would say it is quite good (7).