At the bottom of the sliders is a preset that catches your eye- it reads 'Invert Sex'. That sounds like a simple place to start, and saves you a bunch of messing around with the sliders before you can test this thing.
You click it, see all the sliders invert from their previous positions, and then hit Apply. It starts to load in the changes and adjust the 3D model. And as it does, a tingling sensation spreads through your body and you start to feel... weird. Every time a part of the model changes, you feel this odd shifting in you.
Your skin seems to soften all over, most of your body hair thins or vanishes, and it becomes smooth. Your facial features shift, as your jawline softens and your lips turn puffier. Your larynx shrinks in your neck and your voice softens in pitch. Your shoulders push inwards slightly, the muscles in your arms and legs slims and turns more lithe, and your hands and feet shrink slightly. Your figure seems to change shape a little too, your hips widening and your butt filling out as your torso becomes more petite.
Something that stands out to you is how conflicted your brain feels right now. You've always thought of yourself as a boy, but with how you've started to change, you're starting to question that. Maybe you're actually a girl...
As if in response, your nipples swell and you gasp with pleasure as they grow greatly sensitive. Breasts start to form on your chest, and to your surprise they feel like a natural part of your body. The tide has turned- you're not a boy anymore.
Soon after your breasts have reached full size, the changes reach your crotch. Your penis starts to shrink back into you, your balls move inside your body and reshape to form ovaries that join up with a womb, and your scrotum splits along its middle to form a vaginal opening. Your body is a girl's, and in your head you feel that way.
For the last few seconds before awareness is erased, your mind goes a million miles a second thinking about the change- you've emasculated yourself, you have a pussy now, you can get pregnant now, thinking about a handsome guy with a big cock is kinda turning you on, you must've changed your sexuality from a straight boy to a straight girl, you have nice soft boobs, you really want someone to suck on them...
At last it fades. You forget you were ever a boy, and your now girl self looks at the programme wondering what to do next...