Root Island

Root Island Root Island is a desertous region with little vegetated areas save for the trees that surround the Manhofer Testing Grounds. It is a small island among the Archipelago Island chain, but it is also bigger than Pine Island.

Information
Root Island is the island that is connected to Pine Island via the old Bridge. It serves as the location of the Manhofer Testing Grounds and does not fulfill any other purpose it seems rather than to be a space for the Time Machine to reach Temporal Displacement.

ESA
However, the island does make an appearance in the prequel game to No Time, Edward's Sewer Adventure, the ending of the game resembles Root Island's desert region. Also, at the end of ACT III we can see a young Crimson and the Time Agents plotting a raid on the facility, located in a group on the Southern hill located on the right of the photo of Root Island featured above.