An Overview
Players trying EotA: Twilight for the first time often expect it to be similar to DotA: Allstars, given the two maps' similar names and premises. Upon playing the game, however, enormous differences immediately become clear: DotA is a game focused on heroes, their attributes, their items, and their skills. Pushes are an integral part of the game, but beyond the successive and ultimate destruction of the opposition's base, the focus is much more tactical than strategic. EotA is different. There are still many items available, and they can be upgraded significantly (through "tempering" at the alter, rather than through recipes), but there are other ways to spend gold: Obelisks, mercenary spawns, new outposts, outpost upgrades, command towers—players are never forced to purchase a single "must-have" item.
EotA's depth goes beyond gold use. In addition to gold, there is another resource, crystal, that is earned through killing enemy heroes, and through crystal generators (see below). Players can spend crystal on additional skill, attack, attribute and armor points for their heroes at the alter, as part of the cost for some structures and outpost upgrades, or in exchange for gold at a Goblin Laboratory.
The generators that provide a steady supply of crystal are only one of eight different kinds of generators (all upgradeable, as most everything in EotA is). These generators draw their power from obelisk control towers placed near neutral obelisks. The control granted by these towers has benefits even if it is not used to power generators (every point of excess energy grants 1% bonus experience gain), but much important is the obelisks' other byproduct: Tower cores. Each obelisk control tower provides a tower core for its team once per a set period of time, and controlling more control towers than the enemy grants bonus cores. A player's worker can turn a core into one of several different unit spawn towers. Each spawn tower type has a specific counter, and the team that can best adapt to its opponents' choice of spawns has an advantage.
EotA is different at the micromanagement scale too. Heroes are still the focus, but they are much less lethal than in DotA. Battles last longer because units kill each other more slowly, giving players more time to use their hero abilities. These abilities are highly varied: Each hero has an innate (unleveled) skill, four regular skills, and an ultimate skill. Heroes do not gain skill points every level and all normal skills are six points deep; with so many options available, a given player is only likely to be able to max out a few of his skills, or level them evenly midway.
The functionality of skills is different, too: Many effect values (damage, healing, etc.) are not preset, but adjust in strength based on one of a hero's attributes. Since a hero's skills might not use a hero's primary attribute, this forces players to diversify somewhat, weakening "attribute stacking."
In contrast to most AoS maps, where the heroes of players who leave simply sit idly, the computer automatically assumes control over leavers' heroes in EotA. The hero AI is vicious and versatile, and players can fill in slots with computer-controlled heroes at the start to fill in for missing players, or to play a fully-featured singleplayer game. The AI is no match for experienced players, but it can still challenge those who are learning the game.
Finally, EotA comes with a tournament-style ladder that allow players to use the "-save" and "-load" commands to add their performances to a comprehensive listing.