The nice thing about Overwatch's cast of characters is that you have options. You need attackers to push a good attack successfully, but whether you choose to play as Reaper - a teleporting close-range angel of death that can make himself immune to damage and eats the souls of dead players to heal - or Soldier-76 - A white-haired soldier whose assault rifle, rocket launcher and sprint make him play a little like a Call of Duty character - is up to you. All of the characters are different, but any character of an archetype can fill that same role.
As players select their characters and build a team the game will give you tips: "You don't have any tanks" it'll intone quietly, suggesting your six attacking characters might need heavier support "You have too many snipers" it'll mention offhand, as a half dozen Archer's are chosen to assault the enemy.
What Overwatch does very well is taking your hand to guide you through the act of playing it. Any game can have a tutorial but it's something Blizzard have historically had a lot of trouble with: playing Starcraft 2 often involved watching videos to learn and most mid-range Hearthstone players are reliant on online guides to build the perfect deck for battle.
Here it's all contained within the act of playing the game and there's a genuine sense of progression. After each death you're reminded of your achievements with that character, and if you've broken one of your personal records the game will let you know, fixing your score to an online equivalent of the fridge door like a proud parent.
There's metagame progression, allowing players to level up between games and more crucially unlock chests (no money is mentioned here, but I think it's likely they'll be selling chests for real money sometime after launch) containing new costumes, lines of dialogue and win poses you can use to customise characters.
I'm always a little leery of customisation in competitive games - getting serious about my shooting for a bit, messing with the silhouettes and colour schemes of individual characters can mess up your quick recognition and is a trap Dota 2 certainly fell into, but I also recognise that it's very popular with a lot of people and encourages people to play for longer, so additional skins are always going to be a thing. I do hope we don't see any skins that massively change the look of characters.
It also performs really well. I've got a decent graphics card - a 970 GTX - but a slightly creaky CPU - an Intel I5 4430 - and even at its most hectic with all of the graphics settings maxed out I've never seen a dip below 60fps. I'm not the framerate police, but it's a pretty game and it's nice to see no noticeable performance hitches, even in a beta.
Overwatch might be different to what you expect - a heavier focus on working together and with the flow of combat being controlled by abilities with cooldowns but I think with this second Beta Blizzard have managed to prove that they've got everything in hand. With Blizzard behind it and the strength of what i've seen so far, this is almost guaranteed to be a success and I'm really excited to spend more time with it.
Small details: I turned off the HUD for most of these screenshots, and a couple of them are promotional images that looked pretty. Honestly, gorgeous character designs.