The truly great action films of our time — "Die Hard," "The Road Warrior," "Aliens," say — can be summed up in one word: relentless. Once they get in gear, they put the pedal to the metal and don't slow down.

The classic arcade games of the 1980s could be called relentless: "Asteroids," "Defender" and even "Ms. Pac-Man" didn't give you many chances to catch your breath. But as games have gotten more complex, their big action sequences are surrounded by a lot of down time.

Much as I love "Grand Theft Auto IV" and "Metal Gear Solid 4," they take awhile to get going.

Not the games reviewed here. Each one starts with a bang and doesn't let up.

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"Ninja Gaiden II" (Microsoft, for the Xbox 360, $59.99)If you expect your ninjas to be at least a little stealthy, Ryu Hayabusa isn't the man for you. Ryu's technique is to leap into action with sword (and staff, shuriken, flail and tonfa) flying. Your enemies don't back down easily, either: Some keep attacking even after you've hacked their limbs off.The action is satisfying and the graphics are impressive, but the game has some major failings. One is a wonky camera that often blocks the best view of the action and prevents you from seeing approaching monsters. The other is an incomprehensible story, which at times becomes unintentionally funny. Still, if all you're looking for is a pure adrenaline rush, "Ninja Gaiden II" delivers. Three stars.•

"Robert Ludlum's The Bourne Conspiracy" (Sierra, for the Xbox 360, PlayStation 3, $59.99)While Jason Bourne may be a $30 million killing machine, his moves are easy enough for fighting-game novices to handle. Still, you really need to master the timing to be effective. Land enough punches and you can activate a "takedown," which allows Bourne to use environmental objects — a desk, a vending machine, a neon sign — to inflict real pain. Shooting and driving sequences are much less entertaining, with stiff controls that don't deliver the same visceral kick.Three stars.•

"Haze" (Ubisoft, for the PlayStation 3, $59.99)This heavily promoted first-person shooter heaves you right into a futuristic war between Mantel Global Industries, a private military contractor, and The Promise Hand, a South American guerrilla army. You begin as a Mantel trooper, teamed with some of the most loathsome characters ever seen in a game, but eventually you switch allegiances. (That's not a spoiler; the manual gives it away.)Unfortunately, the artificial intelligence is dreadful, making your squadmates on either side stupid and nearly useless.One star.