On the second storey of an old warehouse in Tai Seng, a small group of people are huddled. Below, mutants roam - poised to eliminate the last human survivors in post-apocalyptic Singapore.

The survivors - there to gather supplies and armed with limited weapons and ammunition - have to figure out a way to escape. Or they can try to find a cure to save humanity from extinction.

No, this is not a scene from the latest zombie movie, but part of a new interactive and experiential role- playing game called Mutants & Mayhem. It is among a slew of new urban games created by companies here this year.

Mutants & Mayhemis the brainchild of Mr Raihan Harun and Ms Joanne Lim, both 36. They run start-up Void Deck Games, which touts itself as Singapore's first immersive simulation games company.

Mr Raihan says they created this game to allow participants to experience a fantasy - what it is like to live through a zombie apocalypse.

In the game, people play a human or a mutant. Humans have to choose between escaping from their base and finding a cure, while the mutants' goal is to infect all remaining humans. The humans fight off the mutants using Nerf guns and foam swords, while the mutants get into character with the help of a face-painting service and other props.

Mr Raihan and Ms Lim are involved in each game session as "storyteller" characters who help to facilitate the flow of the story.

He says: "Players on both sides are encouraged to role-play with these characters.

"Player interactions and decision-making shape the outcome of the story, which could end in at least four different ways."

The game had its first run last month and about 130 people have played it so far. It will run every weekend until the end of the year. Prices start from $50 a player for a two-hour session.

There are up to two sessions a day, depending on the number of people who sign up. At least 15 players - five to play humans and 10 to play mutants - are required for each game. Up to 25 people can play at one time.

The game almost did not take off because finding a location to hold it was a challenge.

Mr Raihan says: "It was hard to find a large industrial space that was willing to open its doors during off-peak hours for strangers to come in and have a good time."

The company eventually managed to rent space in a four-storey warehouse from trading company Alltrust International. The game is held on the first two storeys of the warehouse.

Much work goes on behind the scenes before each game, with preparations starting seven hours before a session.

These include rehearsals for the "storyteller" characters, costume and prop maintenance, and setting up the scene.

The game lasts up to two hours, "depending on whether the humans can survive that long", says Mr Raihan.

While there have been no accidents so far, he adds that he has witnessed players being immersed in the game, for instance, becoming so "paralysed with fear" that they "failed to run from the mutants".

Another player, Mr Raihan recalls, was so "lost in the moment" that he "rained blows on everybody with his foam swords".

Void Deck Games intends to launch a sequel to the game on an offshore island next year and has another game - an espionage scenario set in the heart of the city - in the works.

Another urban game here is Water Tag, introduced earlier this year by The Wow Experience, which runs sports activities.

It is the wet version of laser tag. Players, who pay from $28 a person, don water tag vests and carry water guns. Their aim is to shoot at their opponents until indicators on the vests show they are completely filled with water, after which they are out of the game.

The game can be played anywhere, though proximity to a water source is preferred.

A spokesman for The Wow Experience says: "It's a great way for people to have fun and cool off at the same time in hot, sunny Singapore."

Other urban games are one-off events, such as the Singapore Office Chair Race, which will be held this weekend, and Wonderland, which is said to be the first large-scale version of the escape game designed for a mall here.

The Office Chair Race is a collaboration among the organisers of video-game convention GameStart and Singapore chair manufacturer Secretlab.

In the race, two participants push themselves on office chairs, using their legs only, over a 40m obstacle course.

Races are held across two days and the five fastest racers on each day win prizes that range from mugs and T-shirts to a Secretlab ergonomic chair worth $529.

Secretlab's co-founder Alaric Choo says the race is a new concept here. "If it is popular, we have a number of other ideas that we are keen to implement."

As for Wonderland, inspired by the classic tale of Alice In Wonderland, it is a large-scale version of the conventional escape game and will be played in Jurong Point next weekend. Parts of the mall will also be dressed up in the Wonderland theme.

As is the case in escape games, players - participation fees are $20 for a single player and $120 for a team of six -will work together to solve puzzles within a time limit.

But unlike a conventional escape game, they will not be confined to a room as the game will be played mall-wide.

There will be 11 game sessions across two days, before a finale on the second day where top teams from earlier rounds will compete for the grand prize - $5,000 worth of Jurong Point vouchers.