Warcraft series fans will recognize Jaina and Thrall, representatives of the Alliance and Horde factions, respectively. Both characters' appearances seem based on earlier versions of themselves rather than their current visage, as Thrall is once more clad in his Warcraft 3 armor, while Jaina lacks the distinct white hair she gained in the latest World of Warcraft expansion. The Lost Vikings, meanwhile, are from an old SNES game called ... well, The Lost Vikings. Thrall will act as a melee fighter, Jaina a glass-cannon mage, and the Vikings as a trio of individually-controlled characters.
The game's new maps feature Egyptian-inspired themes, with one set above ground (Sky Temple) and one set in the catacombs below (Tomb of the Spider Queen). Sky Temple encourages players to capture control points which will in turn cause heavy damage to enemies and their base, while Tomb of the Spider Queen rewards players for stealing minion souls by summoning strong monster allies.
If you're anxious to try these additions out for yourself but aren't part of the alpha currently underway, you may not have to wait much longer: Heroes of the Storm will move to closed beta starting January 13, 2015.