Hot Hardware published a review on the Overwatch PC Gameplay And Performance: Blizzard's First Shooter Soars High A quote from the article:

Overwatch, the team-based multiplayer shooter from Blizzard Entertainment has proven to be an unstoppable force in the industry having now reached the hands of more than 7 million gamers within a week of launch. Many predicted as much once the early beta saw nearly 10 million users. Admittedly, we too have been immovably glued to the game since installing the PC version early last week. It features a wide variety of characters, and play styles, with frenetic-pace gameplay that is easy and intuitive for casual players. Yet Overwatch dishes out plenty of depth and strategy for crafty players who strive at filling specific roles in a team-based setting...

 Overwatch PC Gameplay And Performance Review: Blizzard's First Shooter Soars High @ HotHardware