Complex sentence: It is the fourth installment in the "RollerCoaster Tycoon" series, though it will be the first portable edition of the game, as it will be exclusive to the Nintendo 3DS.
Split into simpler sentences: It is the fourth installment in the "RollerCoaster Tycoon" series. It will be the first portable edition of the game, as it will be exclusive to the Nintendo 3DS.