It would be cool to see some form of X-ray within the game. I don't know if this is possible, but I know of two ways this -could- be done;
1: I think the easiest way would be to simply add a small box to the UI where the x-ray is seen. Something like this: http://tinyurl.com/hkw83j8
2: The other option is the make the x-ray appear on the bodies of the characters, like at the females' abdomen. This way might be a bit harder, but it looks better in my opinion. Example: http://tinyurl.com/jgpgu8p
My second suggestion is kind of related to my first one. It would be awesome if the game could include cervix penetration. This could probably be done with flexes such as the ones that controls the pussy and the ass and that reacts when the cock pushes against it. Like, how much it will dimple inwards due to the force and how hard it would be to squeeze through it.