I don't mind long hair but it comes down to how the character wears it. Like I'm more interested in a character if they wear their hair in a high ponytail rather than low
Voiced VNs really add more to the story and I enjoy it very much, but I also understand that hiring voice actors can be quite expensive especially when the story has so many routes and characters so I appreciate partial voice acting as much as full voice acting
Mostly the Art style, length, and completeness of the game. There are so many good VNs and dating Sims out there and when I play a game, most of the time I put in good hours in one sitting so playing demos doesn't do it for me.