I think I've just come up with an idea that trumps all the others that've been put forward so far.
We change nothing about Usagi's life, not directly anyways. We don't change any of the core rules of the Sailor Moon universe so the Silver Crystal doesn't have any additional powers, and the other Senshi are no different from normal either. What we change is the year Usagi is born in.
Usagi is an avid gamer, as we see quite often early in the series and again and again throughout the later seasons as well. But in the early 1990s, there aren't a whole lot of games around that challenge one's intellect so Usagi isn't really getting anything out of the experience.
But push the timeline forwards about ten years or so and you see something very interesting happen to video games; they become more complicated, they start demanding more thought from their players. Specifically, there's one game in particular released in 2001 that will grab Usagi's attention because Shingo keeps beating her at it, and make her play and play until she's mastered it completely and kicking his ass.
That game is
Halo, ladies and gentlemen.
Now imagine what Usagi will be like when she's effectively using the Master Chief as a role model and invoking
I Know Mortal Kombat on a regular basis. At the very least she is evaluating combat situations the same way she would on Legendary difficulty, which means no leaping out from behind cover and making a speech; against a single enemy you use stealth if at all possible, sneak up behind the guy and crack him on the head. Now imagine the other Senshi getting into the act as well with the games
they've been playing; Jupiter + Guilty Gear, anybody?
*Sits back and headbangs to
Unyielding*