Alright, I'll try to explain the game as best as I can.
You get 1 - 5 demigods to a team on both the forces of good, and the forces of evil. Their coloration is different, but as far as gameplay both sides are otherwise identical. You can be an assassin which is a one man army, or a general who *has* an army. In beta 1, what we're playing now, we only have one stage, which is 3 vs 3, and 3 demigods to choose from, all of whom are assassins. Beta 1a will be released later this week, where we will get a new 2 vs 2 map, and we will be able to play as another assassin, the Unclean Beast.
Both teams start with a base on their side of the map. Their base includes stores for helmets, boots, armor, gloves, and rings, all of which improve the player's stats in various ways. They have a healing crystal, which quickly heals demigods who stand near it. There are also gold mines, which provide money for all demigods on the team who own them. They have portals, which create ai controlled monsters to fight for the army of the players who control that portal. The most important structure in a team's base is their stronghold. The game is won when one team destroys the enemy stronghold.
Other features on the stage worth noting include the towers of light, which defend both teams bases. The towers fire energy beams at enemy monsters and demigods, and can "link" to other nearby towers when firing, increasing their damage. There are archer towers which work similarly, but fire arrows instead of beams of light. In the center of the stage is a flag. Having a demigod stand near the flag will start to capture it for their team. Once the flag has been captured, that team's portals will create a larger amount of monsters to fight for them, giving their team the advantage in battle.
Doing things like killing enemy monsters and players will give your character experience points, and upon levelling up they get a skill point which they can use to gain a number of upgrades. They have the option to spend their skill point on a statistical upgrade, which will give them more hp, mp, attack speed, damage, regeneration, and so forth. They can buy passive skills which will improve their character in some way that does not requre player input. Examples of this are the Rook's archer tower upgrade, which causes arrows to be fired at enemies near him automatically, or the Torch Bearer's permafrost upgrade, which slows the attacks of enemies who are near him while he is in his ice form. Lastly, there are active skills which require the player to use them as special abilities. Usually these cost a certain amount of a player's magic energy, and have cooldown times before they can be used again, like in your standard rpg. There are also upgrades to active abilities to make them stronger.
Your team of demigods tries to evade or destroy the enemy defenses, in order to take out their stronghold. If a demigod is killed, they have to wait a certain amount of time before they can respawn. Capturing the center flag to get a better army is usually an important part of pushing through the other team's army. There are also flags adjacent to both teams' portals and gold mines. Capturing these will give your team the huge advantage of having allied monsters coming through right next to the enemy's base.
Does that explain the game well enough to get an idea of how it works?