The game comprises two factions that battle against one another. The factions, the Hellbourne and the Legion, offer players a wide variety of unique heroes that the player controls in the game. The heroes of each faction are organized into three categories; strength, intelligence and agility. Currently there are 26 heroes on the Legion side, and 27 on the Hellbourne side. Every hero comes with their own unique style of play and their own animations and sounds, much like in DotA. Although many of the heroes were directly transferred from DotA, there are a few new ones as well.
Each unique hero has four special abilities that help them with their conquest of the opposing faction's base. Heroes start at level 1 but can eventually reach level 25, depending on how long the game lasts. Each faction has its own base on opposing sides of the map and these bases each contain numerous buildings, the most important being the barracks, towers, and one guardian building which ends the game when destroyed. These guardian structures, however, are heavily guarded by "creeps" and numerous towers - to destroy one, a team must "push" through at least one lane and destroy all 3 towers in that lane. Once all three towers in a lane are destroyed, the team has the option of destroying the ranged and melee barracks, then the two towers that directly defend the guardian structure. Only then can you attack the guardian structure itself.
There are also bug fixes including improved collision detection, improved attack animations, improved headshot detection, removal of known exploits on all official maps, and improved healing tool functionality - no more "false positives" where the healing animation plays but no actual healing occured.
All in all a massive new update. New weapons, a new perk (player class), a new Specimen, a heal dart - with this medics can now heal from a distance - and all the rest. I'm looking forward to playing this game even more :)