What I´m mostly looking for is hours of gameplay - it doesn´t have to involve a harem - just if possible many girls to go for. Also finished or at least 50%+ done.
I´ve already played My new life and Man of the house.
I would gladly try out any suggestions.
Ecchi Sensei and Waifu Academy are the most impressive Ren'py games I have managed to find aside from Harem Hotel. There is a surprising amount of over-lap in the elements of the two games, so I would say it comes down to if you would prefer to be an adult teacher (the former), or a student (the latter). All things being equal, I would say Ecchi does a better job with character development and narrative depth, but they are remarkably similar. Fair warning - Ecchi does eventually jump into the deep-end of the incest pool, though that is only a couple of the 20 or so relations the PC has. But if that bothers you acutely, you may not enjoy those parts (though I am pretty sure you have the option to skip any or all scenes you do not wish to do).
To me, what makes Harem Hotel comparatively impressive is the incredibly smooth animations, but most importantly that all the characters have actual personalities and motivations that make them feel three-dimensional. If you enjoyed HH for the same reasons, I do not think you are likely to find anything here that does a better job in those aspects, than Ecchi Sensei. If you do, by all means, feel free to let me know.