Complex sentence: After finishing the opening missions, the player can freely explore the game world, undertaking side missions and several other activities, though some areas remain inaccessible until certain milestones in the main story are achieved.
Split into simpler sentences: After finishing the opening missions, the player can freely explore the game world, undertaking side missions and several other activities. However, some areas remain inaccessible until certain milestones in the main story are achieved.