We also happen to have a Krogan in our party. He's working through some issues several yards away, cursing and firing his rifle into the ocean. It's a little awkward.

This is the kind of emotionally conflicted scenario that BioWare president Greg Zeschuk and project director Casey Hudson hope will leave an impression on players of the company's epic upcoming space-set roleplaying game Mass Effect. Even after only having been familiar with honorable Krogan bounty hunter Wrex for a few short moments, the journalists watching Zeschuk and Hudson demonstrate the game in a closed-doors session were themselves visibly resistant to seeing the BioWare developers take the hard line approach and screw over protagonist Shepard's buddy.

The dilemma can resolve--or not--in different ways, depending on how the player handles the situation, but in the interest of keeping the crucial plot points under wraps before the game is released, we were asked not to write about the particular route taken during the demo session.

Of course, in addition to the various resolutions available once Wrex is faced with the nearly impossible decision of saving the world or saving his own race, it may well work out that during your playthrough you never bring Wrex into your party to begin with, bypassing that uncomfortable exchange.

Earlier in the demo, Commander Shepard arrived at the space station and attempted to sneak by Wrex to get to an elevator. He had killed one of Wrex's bounty contracts--and Wrex is infamously fastidious when it comes to finishing what he starts. The BioWare folks failed at sneaking Shepard past--surely deliberately, for the purposes of the demo--and Wrex confronted him. Like the later Wrex situation, it can be handled in different ways. Wrex is a bit of a hardass, but he also respects integrity, and standing your ground when dealing with him can yield positive results. After a bit of back-and-forth, Wrex joined Shepard's party.

Mass Effect's conversation engine, which is at the center of these encounters, is one of the game's strengths. As in most dialogue-infused games, conversations are fundamentally built around a dialogue tree, but here are presented in a more cinematic fashions. Rather than simply staying focused on one talking head, or switching between two, conversations are shown through a variety of cycling camera angles, sometimes pulling back to a groupshot, sometimes focusing in on a closeup, sometimes in between. Well-implemented depth of field effects put the spotlight on the speaking characters while retaining a view of the gorgeous surrounding environments.

Conversation options are presented as soon as the NPC begins talking, and as you select choices the game will assemble them into a conversation--alternatively, a double dap of the button interjects the response. This actually affects the conversation, as your character comes off as rude. Certain additional dialogue options--beyond the standard three-tiered range--may appear depending on both the situation and on relevant skills your character may have.

All in all, Mass Effect is a gorgeous game, with clearly a great deal of effort expended on both its locales and its characters. The level of detail extends far and wide: during a trip to a planet from which a static-obscured distress call had been sent out, the team dropped a six-wheeled personnel transport into a shallow body of water on the surface, and after zooming in it was possible to see droplets of water cascading off the vehicle's armor.

Unfortunately, the dreaded "uncanny valley" makes an appearance from time to time, largely in characters' eyes--despite well animated body language and facial movement, characters often appear to be in a fixed gaze, which detracts from the otherwise extremely convincing presentation.

Though the presentational elements were the focus of the E3 demo, Zeschuk and Hudson were also sure to show off the game's scale, via its galactic map. From your ship, you can manipulate a map that begins at the planetary level and can be zoomed out to a solar system scale, then again to a star cluster scale, and finally to encompass the entire galaxy. The developers were quick to point out that players can visit any planet, some of which are crucial to the story but many of which are entirely optional, offering subplots and additional exploration for players who want it.

Meanwhile, a refreshingly retro synthesizer-tinged musical score permeates the world, evoking the kind of desolate but subtly epic old-school sci-fi that is more in line with Metroid than with Halo. Mass Effect's score has more of a 1970s flair than does Metroid, however, bringing to mind the early ages of synthesizers. The effect is completed by the light film grain effect applied over the game's visuals, creating strong, coherent atmosphere.

Gameplay videos released on the internet in recent days suggest that not every scene in Mass Effect may be up to the same standard of writing and narrative impact as the standout Wrex incident, which might be an issue inherent to making a game on this scale. That said, the company has demonstrated plenty of top-notch material already created, built around what appears to be an extremely solid core. With BioWare's existing track record, it seems likely the studio will deliver.

Get the Flash Player to see this player.