While free, downloadable demos have revolutionized the art of shopping for games, they’re not for everyone. If you’ve got a well-developed sense of your likes and dislikes, demos can feel like a waste of time. Though some publishers are working on ways to reward those who try demos, players often end up replaying portions of games once they pick them up at retail. Who wants to waste time playing some early chapter twice?

Players of "Dead Rising 2: Case Zero" will be able to dress protagonist Chuck Greene in a variety of bizarre get-ups.

“Dead Rising 2: Case Zero” gets around that fundamental conundrum by introducing “DR2’s” main character, Chuck Greene, and zombie-slaughtering gameplay, but it’s in a prequel chapter that takes place in a separate location from the retail game. In other words, we won’t be replaying any of this stuff once the main game launches, unless we want to.

“Case Zero” (rated M, $5 download for Xbox 360) meets up with motocross racer Chuck and his daughter, Katey, in the small town of Still Creek. Set some time after the first “Dead Rising,” which told the story of a zombie-creating toxin released into a Denver-area shopping mall, “Case Zero” introduces us to a world where a drug company has created Zombrex, a temporary cure that has to be injected every 12 hours to prevent the infected from turning into shambling, flesh-eating groaners.

Katey and her dad pull into Still Creek to fill up their gas tank, but before long, someone has stolen Chuck’s truck, which includes the doses of Zombrex needed to keep the little girl healthy. Chuck’s mission is to find Katey Zombrex and find a way out of town before the feds come in, quarantine the area and take his daughter away.

As you set about getting Katey her meds and trying to rebuild a busted motorcycle, you’ll get a nice taste for what the world of “Dead Rising” has to offer. If you’re a “Dead Rising” diehard, you’ll appreciate the tweaks and refinements new developer Blue Castle Games has made to the “DR” formula.

Chuck is a motocross star/handyman, so much of the game’s emphasis is on his MacGyver-like ability to combine ordinary items into powerful weapons. A baseball bat and nails, for example, gives you a spiked bat, while a car battery and a metal rake give you a shock-inducing electric rake you can use to clear hordes of zombies.

Like “Dead Rising,” “Case Zero” takes place on a timeline. Chuck has a watch that moves throughout the game, and “Case Zero” is great about reminding you when Katey needs her meds. Because you’ll need ample time to learn what needs to be done, discover all the hidden goodies, experiment with weapon and power-up combinations and generally screw around killing hordes of undead, there’s absolutely no way you’ll be able to complete the game successfully on your first playthrough. Mine ended with the feds arriving and taking Katey away before I could secure the last motorcycle part, though I made it through on try No. 2. I even rescued a bunch of stranded survivors, to boot!

For those who hated the first “Dead Rising,” the refinements to gunplay, additional save slots, smarter survivors and occasional prompts to save outside of a restroom might not be enough to get you to pick up the sequel. Going off of “Case Zero,” “Dead Rising 2” still isn’t going to be the best-looking, smoothest controlling game on the market. And the load times are likely to be a little longer than we’re accustomed to.

But if you’re like me and regard “Dead Rising” as the best “B” video game ever made, “Case Zero” is a fantastic way to whet your appetite for the slaughter to come when the main game launches Sept. 28.

When I fire up “Dead Rising 2” for the first time, my Chuck Greene will be at Level 5, able to jump-kick and sporting a 1950s-style diner-waitress uniform. I can hardly wait.

It’s amazing that no one thought before now to make their game’s “demo” be a cheap, standalone title that can be played in a few hours. For about the price of a game rental, we get to try sample “Dead Rising 2’s” gameplay without taking anything away from our experience with the core game. About the only bad decision publisher Capcom made with “Case Zero” was not making the game available to folks who plan to play “DR2” on the PlayStation 3. Some gamers may balk at having to pay for a “demo,” but with 200 achievement points and narrative nuggets we may not get in the main game, it’s a modest price. ($10 might have been a deal breaker.)
The website GamerBytes notes that upward of 325,000 people have played “Case Zero” and landed on its leaderboards in the week it’s been out, which means its sales have likely exceeded the wildest projections. Here’s hoping we’ll get more teasers like this in the future.