Melissa Scriven, producer of the game, admits that Crazy Taxi was an influence on the way Emergency Mayhem came together. "When you're making a fun, arcade driving game in an open-world city, Crazy Taxi is obviously an essential reference point – no question," she said. Scriven pointed out that there are some differences to their creation, however. "If anything, we've probably got a simpler control system, more insane traffic and of course we have a host of mini-games to play through too – in Emergency Mayhem the chaos doesn't start and finish behind the wheel!"

The game is set in Crisis City, in which increasingly strange problems occur. The player is behind the three emergency services - police, fire, and ambulance, and each service is assigned an emergency as it happens. This means that while playing as the police, the player can't be assigned a task such as extinguishing a fire. "We give the gamer a lot of choice about how they choose to play through the main game, so you could unlock all areas of the city playing as a Paramedic - and this will give a reward in itself - but in order to access all of the game's content you'll have to complete the game with all three of the Emergency Services," said Scriven.

Each service will have their own problems to overcome, all of which are accomplished through various minigames using the Wii-mote. The Fireman is required to pump water through the hose or beat out a fire, for example, while the Paramedic is required to complete games of 'pure skill' - "real precision is required to beat these challenges," according to Scriven. The Cop has to complete more mind-taxing objectives, while racing against the clock.

Crisis City is set out into 8 districts, set out as 4 Precincts with 2 Zones in each - Industrial, The Ports, The Boroughs, and Crisis Central. Each locale features its own landscape and soundtrack, as well as rewarding exploration with various shortcuts and jumps to get around the city. Driving around the city allows the players to choose the mission or minigame they wish to try out, or simply just drive around in the traffic.

As for the minigames and missions themselves, "you'll be jumping off ramps, shooting down shortcuts, using hoses, firing bananas, performing operations, chasing down criminals, racing patients to hospitals, putting out fires – we have all manner of challenges, from the near-conventional to the completely crazy," said Scriven.

The entire game is a race against the clock, with players also having to contend with the 'Mayhem Meter', which graphs how well the city is doing. "Do well and your talents are recognized by the desk-bound, lilly-livered pen-pushers at HQ who assign you to the next (more affluent) Precinct where the Mayhem breaks out again, and your skills are put back to the test!" Scriven explained.

Driving around the city is done with the use of the Wii-mote and Nunchuk, although the + Control Pad can be used to steer as well. The Nunchuk is needed for the single-player mode, however. The game will also feature a multiplayer mode, with 4 players sharing the one Wii-mote in one mode, and a Versus mode for 2 players, in which they go up against each other to prove their skill at the various minigames in Emergency Mayhem.