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Easy, but entertaining
Donning the Ranger uniform of red goggles and a yellow scarf, you assume control of either a male or female protagonist sent to the tropical region of Oblivia to investigate a group called the Pokemon Pinchers. These baddies ride segway-hovercraft-things and the leaders have extremely complex plans that are slowly revealed as you go along.
Now, although typical protocol is catching Pokemon and training them until they are the very best, Rangers do not. Instead of battling, Rangers signify their feelings of friendship to Pokemon by sending swirls of good intentions around them with their bracelet gadgets called Stylers.
One of the new features in Pokemon Ranger: Guardian Signs is the Ranger Signs. When you encounter certain Pokemon like the three legendary dogs Suicune, Raikou and Entei they will leave behind an emblem. After registering the sign into your Styler, you can call upon the legendaries to help you cross chasms, smash large boulders and even walk on water. This feature is a nice touch and it is cool to ride around on their backs. While the new option is used fairly well, it is not frequent enough to make you forget about all those circles.
Cooperative multi-player has also been added in Guardian Signs. Up to four of your friends can join in multi-player missions using the local wireless connection. These quests are still connected to the story, but take place in the past so it is a neat way to continue the narrative even after you have finished the main campaign. While in this mode you have access to several different partner Pokemon that you unlock as you complete missions, and you will level up again since your stats are wiped at the beginning. The only problem is that this mode is fairly simple. You start out with a couple objectives (i.e. capture four Pidgeys) and once you complete those you face off against a boss. I played with one other person and we were flying through the levels, so with three others the missions should be a piece of cake.