These days, one tool has essentially unlocked the world of game development for the masses.
Since it was introduced in 2005, Unity has tried to make creating video games possible for everyone regardless of technical know-how or budget. It was first announced at Apple’s 2006 Worldwide Developer’s Conference and showcased as the first fully powered game engine—a platform with basic graphics capabilities, physics calculations, and some game behaviors already coded in but extensible—for the iPhone. Unity stood largely uncontested on that platform for a couple of years and quickly became a well-known tool among developers.
from Unity at 10: For better—or worse—game development has never been easier