Massively multiplayer online games are not easy to demo. They’re complex. The user interface is often cluttered, a lot is going on, and the controls often require some adjustment. But En Masse Entertainment and Bluehole Studio nevertheless tried their best to convey what it’s like to play their fantasy MMORPG Tera on the show floor at PAX East this weekend.

The game has been in the making for years, and its North American launch is less than a month away. If it succeeds, the title could snare some users away from MMOs such as World of Warcraft or Rift.

En Masse’s senior producer, Brian Knox, and technical producer, Sam Kim, showed members of the media one of Tera’s endgame instances, the Twilight Valley. Once a secluded corner of the world, the valley has been corrupted by the game’s main baddies, the Argons, who have turned the once lush area into a staging ground for their evil experiments.

I played a demonic looking Castanic Sorcerer. As the long-range caster of the group, my job was pretty simple: deal damage and manage aggro (the aggression of a monster). My teammates and I made quick work of the Twilight Valley’s “trash” mobs until we came upon the area’s boss, a Dagonite Crusader, a victim of one of the Argons’ experiments. Here I could see En Masse’s combat philosophy at work as I constantly tried to keep my distance to avoid the boss’ special attacks while simultaneously flinging fire and ice spells and triggering combo skills. Overwhelming? Slightly. Fun? Absolutely!

Tera is a game that seeks to distance itself from the combat conventions of most MMORPGs. Gone are the days of hitting auto attack and getting up to make a sandwich; players will need to give their index fingers a good workout to succeed. There is an increased emphasis on player positioning, timing, and aiming. Yes, aiming. It is entirely possible for attacks and spells to miss, especially when battles require constant movement. Some spells even require that you “paint” your target before firing them off.

Tera’s combo skill system also keeps you on your toes. Not only can you chain your own attacks together for punishing results, you can take advantage of situational combos as well. For example, after being knocked down during one fight, a prompt appeared in the center of the screen telling me I could retaliate if I hit the space bar fast enough. Such opportunities can be easy to miss during the game’s fast-paced action.

Lately, I’ve lamented to my gamer friends that I’ve grown a little tired of traditional massively multiplayer online role-playing games, but Tera has managed to capture my interest. While it did feel a bit easy, it never felt boring. The game world looks beautiful, the combat is engaging, and En Masse is promising endgame support with a reputation system, 11 endgame dungeons, and random world invasions. Although the monthly subscription fees might be a turnoff to some, Tera has the potential to stand out amongst some stiff competition in 2012.