Complex sentence: When a chapter is completed, all trigger points currently accumulated are erased, and the player is taken to a results screen showing how they performed in the chapter, and gaining trigger points based on that performance that can be used in the next chapter.
Split into simpler sentences: When a chapter is completed, all trigger points currently accumulated are erased. The player is taken to a results screen showing how they performed in the chapter, and gains trigger points based on that performance that can be used in the next chapter.