Eviepuss,
I'm glad you enjoyed playing the demo and are excited to learn more about the characters! Although the story is fairly linear (with choices affecting specific scenes, dialogue, and endings), I'm sure the unique moments with each doll will make your repeat-plays equally enjoyable! If you've fallen for all five dolls, you may want to aim for the "full group" good ending - it's difficult to obtain, but the bonus scene is worth it.
Thank you for your kind words about Lyle's character and the story. Doki Doki Dollmaker is romance-focused, but it's also a coming-of-age story. Lyle is trying to adapt to his new environment, cope with loss, and learn about himself as he enters a new stage in his life. You will find that his relationships with Cole, Tilly, and Mr. Mendoza can be just as important to his growth as his relationship with the dolls. I'm happy to hear that these aspects of the story are a welcome addition to the script!
Thanks again for your lovely comment and support!