The 2600 was a whole wacky world of its own. The system didn't actually have any native support for sprites or bitmapped graphics! The graphics chip was designed to implement games similar to Pong, and only natively supported drawing a few blocks of color; games which wanted to display more complex graphics (which is to say, almost all of them) had to abuse this hardware by modifying its registers on a per-scanline (or even an intra-scanline) basis.