Halo 3 and Mass Effect are two of the most anticipated video games this fall. Both are science fiction space epics, and both take full advantage of the graphical ability of the Xbox 360, but while Halo 3 is a true first-person shooter, Mass Effect is a role-playing action game. Both are rated mature.

Developed by Bungie Studios and published by Microsoft Game Studios, Halo 3 is the concluding chapter to the trilogy of games about Earth and humanity confronting multiple alien enemies in a galactic conflict.

Halo 2 ended with the protagonist, Master Chief, stowing away on a Forerunner ship commanded by the final Covenant prophet and headed for Earth. Halo 3 opens on the African plains surrounding Kilimanjaro. The area has been the focus of the Covenant attack on Earth, and they have uncovered a massive Forerunner artifact buried deep underground. The Master Chief and the Arbiter — leading the race of aliens that have split from the Covenant alliance — are now fighting side-by-side, trying to put a stop to the Covenant prophet and the coming Flood.

In terms of game play, Halo 3 is not much different from the first two games. The smooth control scheme is back, so within minutes you’ll have a good grip on moving the Master Chief and firing weapons. The double wielding of weapons is back, and there are some new firearms, too, to make the havoc more intense. There are also new vehicles to use, which are most fun when playing with friends. While one of you drives, up to three of you can operate the weapons that are on the vehicles.

Halo 3 allows for co-op play with up to four people, either on the same console or over Xbox Live, and because you can enable scoring in this mode, you earn points for killing enemies and lose points when a comrade dies.

At the end of Halo 3 we finally learn the name — well, the first name, anyway — of Master Chief. One note of caution, though, is that you’ll want to watch the final credit roll for the cinematic that follows, or you don’t ever see the actual ending of the game. If you’ve already finished Halo 3 but skipped the credits, play through the final sequence again so the ending makes sense.

Mass Effect, from Edmonton’s BioWare Corp. and published by Microsoft Game Studios, is the first game in a planned trilogy set in our near future in which humans have discovered the remnants of an early, technologically advanced civilization and have been able to establish faster-than-light travel.

You play as Commander Shepard, and you start the game by customizing your vision of Commander Shepard, from your gender to your physical and mental attributes, right down to the backstory your character will carry into the game.

Make no mistake, this backstory impacts the game. Even more mind-bending is that the writers and developers at BioWare have come up with a game in which your actions and decisions truly impact the plot. If you choose to not talk to a character early in the game, for example, that character doesn’t have a role in how the story unfolds and is never seen again. If, however, you do talk to that character, they become integral to how everything plays out.

On your ship, the Normandy, you’ll travel from star system to star system, exploring a range of planets and space transports, all while trying to prevent the destruction of the galaxy at the hands of an ancient machine race.

Using clever radial menus, Mass Effect offers tactical and combat game play within a robust but simple role-playing system. You’ll be amazed by the character designs, art direction and graphics of the game. While the story is tinged with melodrama, this is a space opera, after all. The only problem you’ll have is trying to find the hours and hours you’ll need to play it.