Good luck with your game!
I think gameplay, writing and story is much more important than the images. Many games out there have great images, but awful mechanics and story. It's also much easier to update text, so do the images when you know how everything will come together.
Here are some things many games do wrong in my opinion:
- Don't go overboard with dialogue and text. Having less means you can do it properly and the players are less likely to miss it. Bad dialogue is one of the worst things that can happen to a sex scene.
- Make interesting characters. The girls shouldn't just differ visually, but also have different personalities. Maybe the slut is disappointed in your sex-ability or a girl is actually a lesbian and competes with you for other girls?
- Make the characters consistent. When she catches you peeking she might start locking the door. But when she already has given you a blowjob she probably doesn't mind anymore.
- Give the player information. When your sister is in the Bathroom put an icon there. If a dialogue option is new highlight it. If you got a date in a week mark it in the calendar. If a girl is terrified of you have her tell you that or show it in your notes.
- Make the interface efficient and intuitive. I don't want to click four times to go from the kitchen to my room if I do it twice per day.
- Be very careful with events you can only try once. I don't want to save the game before every decision and reload if I don't like the outcome, but I will do that rather than start over.
