Complex sentence: Foldit's developers wanted to attract as many people as possible to the cause of protein folding--so rather than just building a useful science tool, they used gamification (the inclusion of gaming elements) to make Foldit appealing and engaging to the general public.
Split into simpler sentences: Foldit's developers wanted to attract as many people as possible to the cause of protein folding. So, rather than only building a useful science tool, they used gamification (the inclusion of gaming elements) to make Foldit appealing and engaging to the general public.