Killing zombies on fire RAISES your multiplier. Play the game or read before you say anything.
"There's an added element of risk and reward at the games heart burning zombies with explosives earns a greater score multiplier, but a zombie on fire is faster and more dangerous. But that's just common sense."
-IGN
"Doublesix has today announced a new upcoming PSN game called Burn Zombie Burn. Available in early Q1 2009, Burn Zombie Burn is a cartoony arcade shooter which sees you, Bruce, fighting off the undead masses. The emphasis seems to be placed on building up a high score (as all arcade games should). Multipliers are achieved for setting zombies on fire, but doing so also makes them run faster."
-Joystiq [Playstation]
"To get technical, Burn Zombie Burn is a Geometry Wars-like arena shooter (or Smash TV or Robotron-like arena shooter, depending on what year you were born and whether you've been educated in the classics). You're assaulted by craploads of things that will try to kill you while moving in different patterns, and your success is entirely predicated by how well you can maneuver around them, group them up, and blow them away with the right weapon. There's actually a bit more cleverness to it than the usual arena shooter. With a score multiplier based on how many zombies you've set on fire (and thereby made more dangerous), managing the burning crowd becomes something almost like farming, except with shotguns. And it's a bit more engaging to strategize over weapons, powerups, explosives placement, and the utilization of weird gadgets like a gun that lets you suck out a zombie's brain and launch it to draw the rest away from you. It can get pretty screwy, but the game does a good job of easing you into its complexity through its level progression and challenge modes."
-1Up.com
"Layers of strategy: The map layouts, the modes and the various weapons all combine to add an element of strategy to Burn Zombie Burn that I wasn't expecting. For example, you get a score multiplier for each zombie that's on fire, but they die when on fire for longer than six seconds. Ergo, to get the highest score, you wanna torch 'em, run to a wide open space and then blow them all up at once. But! If you're playing Defend Daisy mode (where your girlfriend is hanging out in a Cadillac mid-level), you can't blow them up if they're too close to Daisy, because she'll take damage. So you've got to work with your weapons (like the brain gun) to lure them away, set them on fire and then blow them up. Word of caution watch out for choke points where fast-moving ballerina zombies can box you in."
-Kotaku
"Shooting zombies and earning points, which is key to unlocking later levels and bonuses, is fun and challenging thanks to the scoring system. Shooting zombies earns you a modest number of points, but to really rack up the points you need to get a high modifier going by setting fire to lots of zombies simultaneously. The downside of setting zombies on fire, though, is that while they'll die roughly 30 seconds after being lit, burning zombies are faster than normal and can pose a big problem in mobs. To make matters more complicated, garden-variety zombies aren't the only enemies in the game. Doublesix has tossed in eight different zombie types for you to contend with that run the gamut from the expected slow-moving reanimated corpses to explosive zombies, dancing zombies, and the dreaded super zombies, to name just a few."
-Gamespot.com
Obviously you're wrong, I don't mean to sound rude, but you are.