Why Can a Machine Beat Mario but not Pokemon?

By now, you've probably heard of bots playing video games at superhuman levels. These bots can be programmed explicitly, reacting to set inputs with set outputs, or learn and evolve, reacting in different ways to the same inputs in hopes of finding the optimal responses. These games are complex, and training these machines takes clever combinations of complicated algorithms, repeated simulations, and time. I want to focus on MarI/O and why we can't use a similar approach to beat a game of Pokemon (watch the video in the link above if you are unfamiliar with how it works). Let's compare the games using each of these factors. The way a machine learns is by optimizing some kind of objective function.