Played it at BlizzCon and really excited for its beta and launch, but definitely needs some tuning I feel.
But the world... man, I thought they nailed the world. There really hasn't been a game that's captured the feel of being a Super Hero adequately imo. Sure, there are games that try to capture being Batman or Spiderman or someone specific, but very few games elevate the player to "Super Hero" status. Metzen or Kaplan even said in response to the Titan question that they ultimately wanted to make a game about heroes, and thus Overwatch. Watching the trailer the first time at BlizzCon, I thought it was cool but needed more. But when I got home and watched it again (after playing), I got chills at the line "the world could use a few more heroes."
Anyways, so from a narrative, art, and creative standpoint, I really like the world, and it makes me want Overwatch to be successful and for this 4th IP to grow into more games than just the FPS it is today.
The game is interesting. It's extremely approachable - my wife (who's really not a gamer) picked it up and went 5-8 on her second round. They have a great "remind me" system built into the game so you can learn your own abilities very fast. Changing heroes between rounds is a lot of fun, but also was an extremely interesting decision on Blizzard's part.
Certain heroes are much easier to understand than others, but that makes it feel like those heroes have much larger advantages for skillful play. Widowmaker (Sniper), while fun, is just cake for a good Tracer or Reaper.
Dedicated healing is going to be a contentious design point. It absolutely ruins 1v1 battles when one of you can have an orb that's powering up another 400 health over the course of the fight. Ultimates are fun, but some ultimates are way more badass than others. Hanzo's Dragons kinda shit all over Torbjorn's avatar stance.
The last round I played was on the desert map, which doesn't have a payload (just 2 capture points), and it was weird to go from 5 amazingly fun rounds to something that felt so miserable. Three players (myself on Torbjorn, a Mercy/Medic, and Bastion) held the 2nd control point way too easily. The other three were terrible and new to FPS games and little more than distractions. But we three fended off a team of six, multiple times, without even trying. Bastion was in turret form just out in the open, getting healed by Mercy, and if anyone tried to run around him, my level 3 turret would almost insta-kill them.
The "play of the game" thing at the end of the match is really interesting, and damn, I saw some amazing plays. I was on Reaper and in a gun fight with Hanzo. We were both really low, I ducked behind a wall to reload and grab a health pack. Hanzo killed me with his bouncing arrow. I thought it was awesome. I also totally had the Tracer moment of teleport in, attach sticky bomb to turret, recall out, and damn did it feel badass. For what it's worth, every round had the same flow: attackers captured point 1, but never got point 2.
Oh, and Reaper's reload animation is one of the most badass animations in videogames imo.
TL;DR - Very approachable. Love the world/IP/creative/art style. Great moments of feeling like a badass for players of all skill levels. Skillful play is rewarded on certain heroes. Support/Healing roles might be OP for defense and could have deeper fundamental design issues. THE GAME IS AWESOME even if it has a few small issues.
Also, /nerding out - I got to shake Jeff Kaplan's hand as he was leaving the panel and tell him congratz ^_^ - I hope the Blizzard team feels proud of their work, because the game is awesome.