The Pokemon Go craze landed in Singapore just five days ago, but some new players have had their experiences soured by others who gained an unfair advantage by getting to the game earlier using third-party methods.

The problem persisted through the week, as new players found themselves matched against higher-level players, which disrupted their gameplay and left them unable to earn in-game currency.

Players of the mobile app have to capture virtual creatures known as Pokemon by walking to different locations where various types will spawn.

But there is also a combat element in the game whereby players battle with each other to gain control of various "Gyms" located on the island, usually at landmarks or points of interest like the Singapore Zoo or Mount Faber.

Captured Pokemon have varying degrees of Combat Power (CP) for the battles that range from 10 to over 3,000.

The higher the player's level - which means the more time spent playing the game - the higher the chances of catching a Pokemon with a high CP. More playtime also contributes to players earning more items that can be used to increase their Pokemon's CP.

Yet within hours of the game's release last Saturday, many Gyms were dominated by Pokemon with CP that was physically impossible for new players.

"It's annoying to start the game and immediately be on an uneven playing field," said student Gavin Chen, 19. "They are so far ahead, we can't compete with them."

Players could gain early access to the game - which was first launched on July 6 in Australia, New Zealand and the United States - by installing GPS apps on their phones.

These apps tricked the game's servers into thinking the player was geographically located somewhere else. Using this method of "spoofing" the game, they could get around the region-lock imposed by game developer Niantic.

Thus, some players were able to catch Pokemon from the comfort of their couch as they could "walk" around by using the app to manipulate their GPS.

This gave them an unfair advantage over those who waited for the game's official launch - one of the biggest complaints about the game's late release here.

However, not all high-level players controlling Gyms are "spoofers". Some say they played the game legitimately while overseas.

There were calls by players to report the spoofers to Niantic by taking a screenshot of their impossibly high levels and attaching it to an online report form, which can result in such accounts being banned.

One former spoofer, Mr Arron Lee, 22, said he did so as he was eager to play the game early.

"It felt unfair to wait while players in other countries could play well ahead of us, so I gave up waiting and spoofed," said the full-time national serviceman.

But ever since the game's official release here, Mr Lee has shelved his GPS app for walking shoes, to play the game as it was intended.

In an unusual twist, Mr Lee said he and some other players who used to spoof are now siding with new players to reclaim Gyms. They use their high-level Pokemon to defeat other spoofers in Gyms. But instead of claiming that Gym for themselves, they leave it empty for players at a lower level to gain control and thus earn in-game currency.

"We want to make a small difference to the gaming community to be fair to new players," said Mr Lee.