Hi, first of all thanks for finding it good, it would've most certainly help with the motivation to have comments like that!
About Lustaryu, since it's our very first visual novel (despite being unfinished), we had no idea how much time it'd take to make one, and we aimed for something a bit too big, with too many choices since we wanted each character to be date-able while also having a story, not focusing only on the dating part; we had a lot planned for the next parts, including male characters to have m/m date choices too, but it was way too much work and I wasn't expecting that much when we started; releasing the demo was a way to boost our motivation, but it did the opposite to me.
There's currently no plan to continu Lustaryu as it is in this state, but we're working on another visual novel, one shorter and that doesn't spread in different directions, focusing on the mc and one other. We've already done a lot, I can't predict when we'll finish it, but it'll definitely be done entirely.
On another note, Lustaryu is still a project that both Kyun and I really loves and hold in our hearts, mostly because it includes a lot of our ocs, making them more alive than with just a drawing or even a rp. After we finish the project we're working on, we may redo from scratch Lustaryu, in a way that is more enjoyable for both of us to do, while also giving you (and hopefully other people that enjoyed that unfinished demo) a more finished full one.
I hope this answer is not too long, once more we both thank you for finding it good to play!