Starfield will let you play on both Xbox and PC without having to buy both versions, thanks to Xbox's Play Anywhere feature.
If you're somehow not already familiar, Play Anywhere is Xbox's in-house program that basically means if you buy a supported game on Xbox Series X/S, you can also play it on PC (and cloud) and vice-versa. Your saves transfer between versions seamlessly too, so you can play some of the game on one platform and then hop over to the other and start from the same spot. The feature is pretty much standard for big first-party Xbox releases, but it was only just recently confirmed that Starfield will support it (thanks, Starfield Beyond).
Assuming this functions like literally every other version of Play Anywhere, not only will your progress be consistent across PC and console, but all of your Achievements - not to mention any DLC you scoop up - will automatically be shared between both versions. It's like you own PC and Xbox copies of the game but you only have to pay for one and your saves are the same, which is pretty neat.
It might go without saying, but it's worth clarifying that this deal only works if you buy Starfield directly from Xbox, so don't expect to be able to buy it on Steam and then play it on your Xbox without having to make a separate purchase. Still, I can only imagine this feature being incredibly handy for a lot of folks, myself included, who game on both PC and console.
A recent leak suggests Starfield will have 50 Achievements to unlock at launch - the same number as Skyrim and Fallout 4 had when they released - and now our own Heather Wald is reminded of the one Fallout 4 trophy that still eludes her.