Infocom succeeded at producing games for many reasons. The company was able to compress Zork so that it could run on personal computers and not just mainframes. It created an architecture that allow them to port the games very quickly to any plaform. This capability gave Infocom a distinct advantage over its competitors in a time when no single model of personal computers dominated the market.
Infocom's games sold well because they were easy-to-use and fun to play. A player had to insert a disk, turn the computer on, and the program would start. Playing the games was simple and intuitive as well: type in English sentences, such as, "Hit the troll with the axe" and the program would respond. Like a reader engrossed in a good book, players found themselves hooked for long periods of time.
While the technology behind the games helped drive Infocom's success, the engineering culture proved equally important. Many of the people who created games knew how to write prose that engaged players. They tacitly knew how to design clever puzzles and what made a text-adventure game fun. Their efforts resulted in games that resonated with quality, the product of careful attention to details and a desire to make each game somehow better than the previous one.
Lastly, Infocom's games were the right products for the right time. They filled a niche for highly-educated, well-read audiences who comprised a large portion of personal computer ownership of the early 1980s. The abysmal quality of computer graphics gave Infocom the chance to excel at what it did best: making text-only games
Somewhere down the road when they started making Cornerstone,
Infocom failed, how did this happen?.