Really depends on the writing. Anything that goes on and on is usually not good. There should also be an exciting moment within the first few minutes, to introduce the game and establish that there is good payoff. The number one thing, in my opinion, that kills a VN with decent graphics is bad...
Really good demo. A little heavy on the alpha male nonsense, though. Feels like the writer is overcompensating. Maybe dial that back a touch. Otherwise, really excellent start.