GPO Map differentiates the seven GPO island into three difficulty levels: Easy, Medium, and Hard. The main GPO map is for the Easy GPO island, also called Green GPO. The Medium GPO island is the Blue GPO island, and the Hard GPO island is the Yellow GPO island. All the other GPO islands are not shown on the map and are excluded from this analysis. There are a few things to notice about these GPO islands. The first is that their sizes differ greatly, with Easy GPO being much larger than Medium GPO, and both of those being larger than Hard GPO. The second thing to notice is that the shape of each island also differs. Easy GPO is relatively flat, while Medium GPO has more hills and valleys. Hard GPO is the most rugged, with a lot of cliffs and elevation changes. Finally, the biomes on each island also differ. Easy GPO is mostly grassland, with some forest and Desert areas. Medium GPO has a mix of grassland, forest, Desert, and Snowy biomes. Hard GPO is mostly covered in forest, with some Snowy areas near the top of the island. Based on these differences, it makes sense that the level requirements for each island would be different. Easy GPO should be completed at level 15, Medium GPO should be completed at level 25, and Hard GPo should be completed at level 35.