"Fuel" is big. Several smaller open-world games could probably fit within its immense play area, a collection of zones that the back of the box claims cover 14,000 virtual square kilometers.

The game's conceit is that in an alternate-reality America, global warming has caused flooding and weather disasters, leaving much of the country dangerous to inhabit and the remaining populace leery of using stockpiled fossil fuels.

The extreme-sports enthusiasts of "Fuel" have no such qualms, though, gleefully racing their tricked-out bikes, buggies, cars and trucks through the wastelands in a "MotorStorm"-meets- "Burnout Paradise" fashion.

The post-disaster environment makes for some unusual sights in a racer, such as dead forests and rooftops poking out of lakes as tornadoes and lightning storms rage.

Racers earn fuel for winning events (first place is the only winning spot), and fuel in this game isn't used to gas up the vehicles but as money to purchase new rides, which never seem to need gassing up themselves. There are lots of vehicles to buy, though most are locked away at the start.

The vehicles can be given custom paint jobs but are otherwise unalterable, though the designs have their post-apocalyptic charm. Most specialize in asphalt or off-road driving; some do fairly well at both.

Race events and challenges can be entered at any time from the pause-menu screen or by driving up to the starting line. Each zone has several career events with three difficulty levels, each awarding the victorious player stars and fuel – earn enough stars and new areas open up.

Challenges don't grant stars, but they do give up a hefty amount of fuel. Many challenges require a specific class of vehicle to be owned in order to participate, so having a surplus of fuel isn't a bad idea.

Events range from checkpoint races over rough terrain to knockout races that eliminate the last racer in each lap and seek-and-destroy events where players try to chase down and ram rivals. There are several other kinds of races as well.

When not in an event, players can simply roam the world, driving for miles across the nearly empty wastes – the distances between points of interest can get pretty extreme. There are event start points to find out there, as well as vista points that offer a neat view and wrecked vehicles that grant a new design, or livery, to use on that particular model.

Once players complete or want a break from the solo game, they may take to an online version of the world or create courses of their own with the game's track editor.

PICKS AND PANS

HARRY POTTER AND THE HALF-BLOOD PRINCE

1 1/2 stars

The release of a new "Harry Potter" film wouldn't be complete without the arrival of a new video game. But "Harry Potter and the Half-Blood Prince" feels like a step down from the game based on "Order of the Phoenix." Spells are still cast with flicks and waves of the Wii Remote, but the controls don't feel sensitive or accurate enough – it can take several upward flicks to pull off a casting of the "Wingardium Leviosa" levitation spell, and just try throwing a pot at a hard-to-reach Hogwarts crest.

Wizard duels are entertaining, however, as Harry flings spells at his opponents while dodging their attacks. It can also be fun to brew potions by mixing specific ingredients and boiling them the right amount – though running out of time halfway through and being forced to start over is frustrating. Quidditch matches are simple checkpoint exercises as Harry chases the Snitch through a series of stars.

But while the three games are decent fun and players are still free to roam the grounds of Hogwarts, there just isn't much else to do besides collecting a bunch of crests, and the main plot is cut down to an outline illustrated by awkward scenes using the stiff in-game models.

Nintendo Wii, also for Microsoft Xbox 360, Sony PlayStation 3, PS2, PSP, Nintendo DS, PC; $49.99 ($29.99 to $49.99 for other versions) • Age rating: 10-plus

PLANTS VS. ZOMBIES

3 1/2 stars

A horde of zombies is about to cross the lawn, and the only way to stop them is with an array of flowers, fruits, vegetables and other plants in "Plants Vs. Zombies," a charming and habit-forming variety of the tower-defense genre.

The lawn fills most of the screen, with the zombies approaching from the right. Plants can be placed anywhere on the lawn by spending sunshine, which falls from above or pops out of sunflowers.

The plants include several kinds of pea-firing pods, explosive cherry bombs, wall-nuts (which delay zombies), delayed-activation potato mines, a piranha plant that swallows zombies whole, and many more perennial favorites for fighting the undead.

As the player's arsenal grows, the zombies get tougher and smarter – they put on helmets, use poles to vault over wall-nuts and so on. The trick is to bring a flexible arsenal to each stage and employ it wisely to fend off the shambling hordes. The game also features several alternate modes, including survival mode, puzzles and mini-games.

PC, also for Mac OS; $19.95 (Popcap.com download) • Age rating: Everyone

– Justin Hoeger