“Halo Wars” (rated T, $60 on Xbox 360) is best defined by what it’s not.

Despite the “Halo” name, it’s not a first-person shooter starring a space marine known as Master Chief. Gamers unfamiliar with the title who expect to pull off headshots and stick grenades to opponents while making big floaty jumps will be let down. It’s a strategy game. You build bases and customize a small yet unstoppable army.

But while “Halo Wars” carries the real-time strategy tag, it lacks the nuances of its PC brethren, such as “StarCraft” or “Sins of a Solar Empire.” Instead, it plays more like RTS-lite. You can only build a relatively limited number of units and construct your bases in preset locations. There’s only one type of resource to harvest, and it can be tough to pull off large military operations using some, but not quite all, of your forces.

A polite, even laudatory, way of saying this would be that it doesn’t try to shoehorn keyboard-and-mouse controls into the Xbox 360 gamepad. Because of this, “Halo Wars” is a great initiation to the genre. In the same way “GoldenEye 007” and “Perfect Dark” on the Nintendo 64 introduced console gamers to first-person shooters, “Halo Wars” ” already a million-seller ” might be the first taste younger gamers get of a genre still finding its way on consoles.

Playing for the first time in Skirmish mode, which allows for 1-on-1, 2-on-2 or 3-on-3 matches, it was hard not to think back to my introduction to real-time strategy, firing up “Warcraft II” after deadline at my college newspaper. The training ground for Skirmish Mode is the single-player campaign, which puts you in the role of United Nations Space Command troops trying to keep the alien Covenant forces from controlling powerful ancient weaponry it unearths on a distant world.

Developer Ensemble Studios, which recently closed and split into a number of parts, has crafted 15 varied scenarios, ranging from capturing outposts and escort missions to clearing a ship’s hull of The Flood, the “Halo” series’ signature parasitic alien life form. The campaign, which takes between seven and 15 hours to complete is punctuated by short movies between levels that are nearly of film quality. I’d need to view the two side-by-side, but if my memory serves me correctly, the scenes in “Halo Wars” look as good or better as the animated “Final Fantasy” movie, “The Spirits Within,” from 2001.

While the action on the battlefield isn’t as stunning, your tiny soldiers are rendered in great detail. The first time you watch a Spartan take control of an enemy vehicle, all your G.I. Joe-in-the-sandbox memories come flooding back. (Stephen Totilo of the MTV Multiplayer blog called “Halo Wars” “the best G.I. Joe game ever made.”)

The simple commands fit well with the 360’s controller and rarely feel dumbed down. About the only element missing controlwise is the ability to define groups of units. If I want to make three attack squads of 10 units each, it should be relatively easy to assemble them into semipermanent groups. The only options in group situations are to highlight all units at once, choose all units of any given type or use the thumbstick to gather your forces in an inelegant sweeping motion that often sucks up more guys than you want.

Luckily, you’ll get plenty of chances to practice grouping units and using the D-pad to zoom around the map on your own, rather than at the hands of cutthroat launchers of online attacks. If you want, you and a trusted friend who won’t laugh at you can team up to take on two AIs, or you can fill out a 3-on-3 battle with just yourself and five computer players. In an era where those who pick up a hit game a month after release are often humbled dozens of times before they can even learn the maps, these bot matches are a must.