personally, I don't want to focus on arts that is 18+ because I think that game developers want us to feel the story more instead of oogling to the arts. but since you said that,maybe I should change my perception XD nevertheless,the arts are good~
I see.. I have heard about comiket event runs in Japan a few times a year. did this game sold well there? also, I won't deny a free artwork XD you sure are a generous one though.. I think a some people would put a price to it if they own it.
dark games and bright games leave impact on players, I think I will agree to your idea XD
its interesting right, learning BGM.
I've been into BGM ever since I watched an anime little busters. I downloaded their OST, and heard them all over again. But this year, I just realized about importance of ownership,copyright and so... as I felt guilt and I still want to enjoy the songs, I deleted the ones I downloaded and Bought the song(also the original game) from Steam. The BGM I've been hearing is great! and hence I focused on BGM for each games I'm playing to feel the music XD
anyway, good luck and do your best!!