Unlike games, other media only requires the observer to passively watch as it presents all of its content to you in a neat and complete package. Because games causes the player to engage with it's plot and has the unique ability to hide away content to those who don't look for it or lack the skill to reach it, the story can become quite complex and that more interesting. Movies can't deliberately hide plot points like this. Books won't have a different ending if you finish it quick enough. This is a game specific story telling mechanic, and although video game storytelling is underdeveloped, I would argue that this makes it the ultimate form of narrative.
If you can make a movie out of a video game plot, you have done it wrong. Although games like Resident Evil, Beyond Two Souls, or Dead Space have well written plots for the most part, they don't fully utilize the medium they are placed in. They could have done as well if they were a movie, although heavily edited to better suit it. It's because the plot is straight forward told to you. You don't need to explore much to find any missing parts of the plot. They are just as good of a game as the rest (except Beyond Two Souls), but the reason behind this linear storytelling is because they were written like a movie, this isn't a bad thing since it works for movies, but it fails to fully embrace the medium it's in.
An excellent example of video game storytelling is Bioshock by Irrational Games. You have the "driving plot" pushing you through the game, but what makes it really shine is it's "hidden plot." The game rewards you for going down every hallway. When you do you can find supplies and audio logs to listen to. The audio logs provide you with the hidden plot, something that movies could never hope to accomplish. In a movie you can't hide audio files lying around the scene, the idea is absurd, but in Bioshock the plot is intentionally hidden away from you. You have to search for it in order to know why there is a city at the bottom of the ocean, something the driving plot won't be bothered to tell you. Bioshock also has hidden plot found around the world in the form of posters, blocked off doorways, blood spatters leading to a last word audio log from beneath the skeleton. These environmental hints are just as important to unravel the lore of the world as the audio logs. By giving the player the freedom to view the world freely and at their own pace you can put so much more detail into everything to tell the better story that movies couldn't hope to enjoy.
Another excellent example is Dark Souls by FROM Software. The driving plot is almost non-existent, and everything is told through the hidden plot which takes the form as difficulty, environmental hints, and flavor text. If you lack the skill to get to the late game you won't be able to experience the hidden plot. By doing this every late piece you unlock is rewarding. Getting a weapon from the boss you just defeated and get to read the flavor text to figure out what he added was to the plot. Nothing is more satisfying.
The reason why the story in so many games fall flat is because storytelling in games is relatively new. It hasn't be around as long as movies to learn all of the quarks of the medium. Although we have learned a lot about it such as when telling a story you need to reinforce it through the game play. The story should never be at the expense of the mechanics, and it should be working together flawlessly with it. You need to have a solid driving plot with an interesting hidden plot that gives reason to the players agency. We have the ability to tell the story in a piece-wise way that no other art form can, but as time goes on we will learn more about how to tell a good story, and we will create plots that can rival any story made in existence. Because games are the ultimate art form.
