The reason Gottlieb went back to basics in the early 80s with game designs they had released during the 1970s was for a simple reason - they were really struggling. So to release a single level game saved money and they game didn't need to be designed from scratch as alot of that was also aready done.

Gottlieb was as a company had been sold 3 times in a few years and no money was being put in for further development. Imagine a meeting at the Gottlieb plant in 1973 and them knowing the company would go from being number one to being screwed and on it's last legs 10 years later.

Dave Gottlieb must of been turning in his grave.