Worst Ever

Of course, the answer is not that easy. You could, and people have, written entire articles on the subject. While there are large numbers of large-scale flops, it's easy to forget that there are hundreds upon hundreds of very bad video games which no one remembers, because they were so bad that they thankfully barely saw the light of day.

For example, there existed an Atari 2600 game in which General Custer took revenge by sexually assualting American Indian women tied to cactuses. It's true! And if you broaden your question to include ALL such games, well, it's an almost impossible one to answer, conclusively or not.