Complex sentence: To defeat their enemies, the player must use their guns against them and, for that matter, "Enter the Gungeon" includes over 200 guns and items, which can be found in chests or bought at shops scattared around the floors in the Gungeon.
Split into simpler sentences: To defeat their enemies, the player must use their guns against them. For that matter, "Enter the Gungeon" includes over 200 guns and over 200 items, which can be found in chests or bought at shops scattared around the floors in the Gungeon.