You won't be able to get it unless you're running Windows 10, and the Microsoft Store doesn't come with any of the bells and whistles that gamers have been accustomed to with Steam. But if you're looking at Lara's latest adventure and simply want to get it for a cheaper price, Microsoft actually has a decent offer.
Rise of the Tomb Raider is actually one of the first — if not the first — major AAA title to be launched through the Windows Store, with Microsoft charging $66.29 for the third-person adventure. That's about $10 less than what it'll cost you through Steam, barring any major fluctuations in the exchange rate.
The deal's available for the next week, and the DLC is cheaper too: it'll only cost you $12.29 for Endurance Mode instead of $14.08 (the price through Steam). The fact that anyone would charge that much for an endurance mode is staggering to me, but that's a complaint for another day.
And for those who are interested in how returns work on the Microsoft Store as compared to Steam, here's the information from Microsoft themselves:
Confirm your order was placed within the last thirty (30) days.
Uninstall the software from your computer:
In Windows 10, Windows 8, Windows 7, and Vista: In Control Panel, go to Programs and Features, and then click Uninstall a program. In Windows XP: In Control Panel, go to Add/Remove Programs, and then click on Uninstall a program. Call us at the customer support number located on our Sales and Support page to request a return within thirty (30) days of the date of purchase. You will be asked to confirm that you have uninstalled and have not made any copies of the software. We may also ask you to sign an electronic Letter of Destruction as a condition of your return. After you talk to a customer service agent, the product key will be blocked and you will not be able to install or use the software in the future. Microsoft Store will issue a credit to the same method of purchase you used to purchase the item and send you a return receipt by email.
The system requirements, unsurprisingly, are the same as what's listed on Steam beyond the Windows 10 specifics. The Microsoft Store isn't as cheap as going through some third-party websites, but if you were considering buying the game outright on Steam due to the reviews and good feedback online, this might be a neat alternative. And if you do buy through the store, let us know how you go — and what it's like playing a AAA game that runs through the Windows 10 framework rather than as a traditional desktop application.