Two years ago we inaugurated our coverage of games with two titles that illustrated the light and the dark sides of the format. “Super Mario Galaxy” was a joyous romp through the universe, dripping with inventiveness, clever concepts and family-friendly gameplay. “Grand Theft Auto IV” was its polar opposite: a dark, grimy, nihilistic exaltation of thug culture, casual violence and sadism. They neatly encapsulated the heights electronic entertainment can reach — and the depths to which it can fall.

Through a quirk of timing, precisely two years later, we find ourselves in almost the exact same place, with “Super Mario Galaxy 2” and “Red Dead Redemption” (the successor to “Grand Theft Auto IV”) arriving in the same week. Have those two years witnessed any shift in the dark and light polarities that characterize the extremes of electronic entertainment?

In a way, yes.

Although it seemed impossible to improve upon “Mario Galaxy,” the sequel not only retains the exuberant experience found in the original, but enhances it in every way imaginable.

In between the original and the sequel, Nintendo released the classic 2-D platforming action of “Super Mario Bros.” for the Wii, thus creating a new generation of Mario fans. “Galaxy 2” begins in this more easily managed 2-D world, then gradually introduces more complex controls and environments until the player finds himself traversing lavish 3-D worlds with shifting gravity or soaring through space from one planet to another.

The goals in “Mario” games never change: Find your way past all manner of obstacles until you reach the star at the end of the level. To accomplish this, “Mario” has some new abilities in “Galaxy 2,” such as a cloud suit that allows him to create fluffy, temporary platforms, or a rock suit that allows you to use him like a bowling ball.

Yoshi is also drafted into the space program, where he can use his tongue to grab objects or his glowing power to illuminate hidden platforms. Players can even have a friend help out, with a more fully developed co-op mode that allows another player to hop in and help grab stars.

This is just a pure delight, with nary a single element out of place. There is nothing here to worry any parent, unless they’re concerned about “Mario Galaxy” addiction. Thanks to the more gradual learning curve, an in-game helper and co-op play, this is a good pick for the whole family, even younger gamers. There is joy in here, and families with a Wii shouldn’t pass this one up.

It’s unlikely that Rockstar Games placed the word “redemption” in the title of their follow-up to “Grand Theft Auto IV” from some sense of penitence over their morally appalling games, but they have actually achieved some measure of morality in “Red Dead Redemption.”

Rockstar made its name because of two things. First, they pioneered and developed one of the great “open world” gameplay systems, offering gamers an entire landscape to explore at will. Make no mistake: They are masters of technology and design. Few are in their league.

Unfortunately, the second element contributing to their fame is the appalling content of many of their games. “Grand Theft Auto” began as little more than a carjacking simulator — and grew to encompass all manner of deviant behavior.

“Red Dead Redemption” takes the “Grand Theft Auto IV” engine and design and transplants them to the Old West, and in the process finds a bit of morality. In a surprising change of pace for Rockstar, you play as John Marston, an upright man with a chance to be a noble knight of the West. His quest to capture his former partner in crime takes him to a large (albeit imaginary) swath of border territory called New Austin, where he can help the beautiful rancher’s daughter, rope wild horses, round up the cattle, hunt varmints, bring in wanted desperadoes, and assist the law.

Morality systems — gameplay elements that gauge whether a character is good or bad based upon his actions — are in vogue right now, and Rockstar has done an excellent job of implementing one. Marston can certainly hold up the bank, rob the train, kill the sheriff, ignore the damsel in distress, and shoot the old drunk in the back, but he’ll have an easier time if he doesn’t. An upright man gets discounts in stores and spends less time and money evading the law.

This is still a violent, sometimes absurdly bloody M-rated game. Make no mistake: You’re still killing people, dealing with criminals, and running into ladies of the night. But, for adults, it’s actually a lot of fun. As with all Rockstar games, you don’t have to follow the story at all. If you prefer to spend all of your time hunting for buried treasure, shooting rabbits, or trying to stay on a bucking bronco, that’s just fine.

“Red Dead Redemption” is rated “Mature” for blood, intense violence, nudity, strong language, strong sexual content, use of drugs — and they mean it. The foul language is less than you’ll find in an average episode of “Deadwood,” but the violence is a major part of the gameplay. That said, there’s something quite appealing about a game that allows you to explore a giant, beautifully realized and populated swath of the Old West at your leisure. This is a special achievement in gaming, and it’s fine to see Rockstar finally used its designers’ gifts in something with a moral core.

Thomas L. McDonald is editor-at-large of Games magazine and a catechist in the Diocese of Trenton, New Jersey.