Complex sentence: It was developed over the course of two years, with a year prior to gain approval for the inital idea, as the developers wanted to make a good action game, and to set the stage for Samus's reappearance.
Split into simpler sentences: It was developed over the course of two years, with a year prior to gain approval for the inital idea. The developers wanted to make a good action game, and also to set the stage for Samus's reappearance.