I spent the weekend spent playing the three new Overwatch team-shooter heroes that Blizzard introduced during the annual BlizzCon convention, and they offer some interesting new wrinkles to the game.

The BlizzCon demo introduced one new map (Hollywood) and three new heroes: D.Va, a mech-style tank; Mei, a frost-wielding defense; and Genji, the robot mirror version of the game’s existing ninja, Hanzo. Unsurprisingly, he’s in the offense class.

Now in closed beta, Overwatch is due to have open stress-test weekends before the end of the year, Blizzard executives said. If you missed our rundown of every one of the 18 heroes currently in the beta, you can find all the maps, support heroes and offense here and all the defense heroes and tanks here.

 As a reminder, you can swap Overwatch heroes in mid-game by returning to the spawn point or respawning there after death.

This is the last glimpse of D.Va you're going to see before respawn.

Above: This is the last glimpse of D.Va you’re going to see before respawn.

Image Credit: Blizzard Entertainment

The Widowmaker/sniper killer: D.Va

D.Va is a professional gamer-turned-hero, and she and her mech both show a ton of personality. The mech is huge and pink; her special ability icon looks like an angry bunny. But in-game, she’s all business.

Despite her heavy form and moderate movement speed while in mech mode, she has the ability to boost/glide for short periods, which makes her a lot more maneuverable than many of the tanks.

She also has a Defense Matrix shield that she can aim where you’re looking, so unlike Rienhardt, whose shield is always solidly in front of him, you can protect yourself and anyone behind you from fire from above — including Pharah’s multiple-rocket ultimate and Widowmaker’s deadly sniper fire.

Her normal left- and right-click fire, dual fusion cannons that slow her movement speed, are fine but undramatic.

Her ultimate is fantastic: You bail out of the mech, leaving it on self-destruct mode, and just about any hostiles in line of sight when it goes off will be looking at a respawn timer. The graphic is quite large to warn the opposing team, but this is fast: If you’re not already near cover (or can create your own), you’re dead.

If you take enough damage as D.Va, your mech goes down and you’re in super-squishy humanoid mode. Don’t give D.Va’s human form short shrift: While a shot or three can take her down, that little pistol of hers can pack a punch. I killed more people with D.Va’s human fire than I did as the mech — at least, until I exploded on people.

Once you’ve done enough damage as a human, or if you’re killed, you can resummon the mech.

With the speed boost and shield, you can fly directly at Widowmaker without worry, so D.Va is a direct counter to one of the more-popular (and more deadly) heroes in the game.

Mei's ice wall is an amazing tool.

Above: Mei’s ice wall is an amazing tool.

Image Credit: Blizzard Entertainment

The frost flinger: Mei

Mei rapidly made herself my favorite character, not because this defense player’s attacks hit brutally, but because of the way she can change the game.

Her abilities include a freeze ray (a nice counter for Tracer or other high-mobility heroes), which gradually slows and then stops anything it targets. A right-click throws a volley of frost shards.

One ability, Cryo-Freeze, turned out to be golden in this inexperienced crowd. It looks like a World of Warcraft mage’s ice block: It surrounds Mei in an indestructible ice shield for a few seconds, just long enough for short-attention-span offense to move to another target and then get nailed by a freeze ray from behind.

Mei moves at average speed for defense.

She offers one additional amazing ability: She can raise a wall of ice that completely blocks roughly two-thirds of a city street.