Niantic's ambitious challenge to "Pokemon Go" players is over. Pokemon trainers around the world proved up to the task as they managed to catch over three billion Pokemon in less than a week.

The game announced on Twitter that its players have completed the Global Catch Challenge, where players were tasked to catch three billion Pokemon within a week. With the achievement, they have unlocked all of the reward sets that Niantic promised.

The biggest prize for reaching the target number of caught Pokemon is the rare Pokemon Farfetch'd. It has been unlocked and will be available to all "Pokemon Go" players in all countries. Although the Pokemon will only appear for 48 hours, it is still a big step towards completing the Pokedex of many players.

Another reward that "Pokemon Go" trainers have unlocked upon completing the Global Catch Challenge was the Pokemon Kangaskhan. Previously, the Pokemon was only available in Oceania region, but after the challenge was completed, the Pokemon can now be caught in East Asia. However, there is also a time limitation to this reward. Similar to Farfetch'd, Kangaskhan will only be available for 48 hours.

The challenge started on Nov. 20, and after one day, the game reported on its Twitter account that its players have caught almost 300 million Pokemon.

Before the second day ended, trainers hit the 500 million mark and unlocked the first set of rewards, which doubled the experience and lengthened lure durations. With it, Niantic also increased the spawn frequency of the monsters, which allowed players to encounter more Pokemon.

By the third day of the challenge, players were able to hit the one billion mark, and reached the 1.5 billion mark the following day. This unlocked more rewards for players, and the spawn frequency of Pokemon were increased further.

By the sixth day of the challenge, players were easily able to get to the three billion goal well within the deadline set by Niantic.