Overwatch is having a "free weekend", meaning anyone can download the full game for free (PC, XBOXOne, PS4) and play it for the duration of the weekend. After the weekend you'll still need to buy it to keep playing, but all your progress will carry over from the free weekend.
My wife and I have been playing the hell out of it for the PS4, I got it shortly after it first came out and I am happy to see how much Blizzard has been improving on it and adding new content without making it paid DLC and whatnot.
They just added a 3v3 elimination match where once you die you are out until one team or the other is completely eliminated. It immediately became the most popular mode (at least on the PS4) to the extent that everyone pretty much jumped out of the objective-based season competitive rankings to play it. There is a good reason for that, though, as it somehow hits the sweet spot of the character-based gameplay and comes of feeling along the lines of a balanced out Marvel vs Capcom 3 in FPS format. The characters
really mesh well with this mode and the matches are fast and frequent, usually lasting about 5-8 minutes a piece (counting the entire best 3 out of 5 round). It is an absolute blast that made a good game better.
I like to play support/defensive roles usually so in the game I tend to main the snipers (Black Widow and Ana) or Mei or Symmetra for defense, but Sombra is quickly becoming another favorite as I can provide stealth support with her.
my final overwatch review: 'what if there was tf2, except nothing ever happened in it'
I can't speak for the PC or XBOXOne, but on the PS4 at least that is not the case at all. The matches are almost consistently tight and tactical with great pacing (more so with the newly added arcade modes, especially with the elimination 3v3). Prior to the last update finding matches was no problem, but after this last update (which added the elimination 3v3) pretty much everyone jumped out of every other mode to play e3v3 so right now it is slim pickings outside it. I don't have a problem with that myself, because the e3v3 is perfect and probably the most fun I've had in a FPS since GoldenEye/Perfect Dark or Quake 3/Unreal Tournament.