I don't believe this is a possible goal. The "entertainment value" of something is very subjective.
If you know exactly what reaction you want to invoke, sure you might use biometrics to measure this. If you want to excite the player, you might measure their pulse, adrenaline levels, etc, but measuring a physical reaction isn't the same as how enjoyable it is.
Besides, what makes one game enjoyable may be completely different than what makes another game enjoyable. Some games are meant to be contemplative and somewhat depressing, rather than pulse-pounding action.
One of the video series I watch, Errant Signal did an excellent video on this topic of what makes games enjoyable called An Aimless Diatribe On Fun. It does a great job answering this question and I believe addresses some of the academic research into the area.
A good quote from that video:
"Think of what it does to a potentially vibrant and expressive artform when out of the gate the expectations for its emtional range is just this one little thing. It's tantamount to saying "Pictures need to be pretty" or that "Music needs to be catchy", but some of the most powerful pictures of all time are anything but pretty, and some of the most powerful music ever composed defies toe-tapping catchiness".