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 downtime. 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. They may not have the depth of a sophisticated role-playing game such as "Lost Odyssey," but sometimes all you want is the video-game equivalent of a popcorn movie.

*** "Ninja Gaiden" has a well-earned reputation as one of the most difficult games on the original Xbox. While it does make some concessions to less-skilled players, "Ninja Gaiden II" still provides enough of a challenge for hardcore veterans. 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 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: wonky camera angles, an incomprehensible story. Still, if all you're looking for is a pure adrenaline rush, "Ninja Gaiden II" delivers.

*** The Matt Damon "Bourne" movies are nearly perfect examples of the hyperkinetic Hollywood thriller. Developer High Moon Studios has done a fine job translating the story into a game. 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.

* This heavily promoted first-person shooter heaves you right into a futuristic war between a private military contractor and a South American guerrilla army. You begin on one side, teamed with some of the most loathsome characters ever seen in a game, but eventually you switch allegiances. Unfortunately, the artificial intelligence is dreadful, making your squadmates on either side stupid and nearly useless. "Haze" is further marred by unimaginative level design, sloppy graphics and repetitive audio. With so many first-rate shooters on the market, "Haze" is a waste of time and money.