In most 2D platformers, the player only had to reach a single goal to complete a level, but in Mario 64 each level contained a mission-based structure that rewarded items needed to unlock new areas. Many 3D platformers followed this trend such as Banjo-Kazooie, Spyro the Dragon, and Donkey Kong 64 creating the "collect-a-thon" genre. This allowed for more efficient use of large 3D areas and rewarded the player for thorough exploration of their environment, but also contained less jumping and involved more elements of action-adventure games.