Something that exists in two forms

The first thing that came to mind which exists in two forms is Resident Evil. It began its life as a video game and was then mutated into a movie trilogy. The first game came out in 1996 on the Sony Playstation and was met with praise for its style and originality. Because of its success, two other games were commissioned, Resident Evil 2 and Resident Evil 3: Nemesis. In 2005, Resident Evil 4 was released and is considered to be the best game in the series and also one of the best games ever released on the Playstation 2.
In 2002, the first Resident Evil film was released. The film had mixed reviews. Some praised it for its similarity to the game but others criticized it for being too much of a standard horror film and not having any meaningful dialogue. Despite the mixed reviews, it was a commercial success and two other films were made: Resident Evil: Apocalypse and Resident Evil: Extension.
I have played the games and saw the films and in my opinion, the games are better, especially Resident Evil 4. The reason I think they are better is simple, one interacts much more with the games than with the films. For me its all about the scare factor, I love horror films and I want them to scare me. The Resident Evil movies did not scare me because they adhere too much to the standard Hollywood horror formula. Sure one might jump when a zombie suddenly appears on screen but we are so used to that trick that it is almost expected in a horror film at this stage. Resident Evil 4 (the game) scared me much more than the films for a couple of reasons. The main reason is that it is a game, you are control of the main character so your decisions affect what happens. With the films, you know that the main character is not going to die, but with the game, you can, and do die (a lot). There is more of a sense of danger to the game because of this. Also, in the films when Alice, the main character gets hurt, it does not really affect the audience. With the game however, when you get cut with a chainsaw, you know because the controller vibrates. This is a representation of the characters pain, and you do not get this with the films.
Usually with third person shooter games one is able to move the camera around the character to see the surroundings. In Resident Evil 4 and the other games, this can be done but only to a certain extent. When you are walking up to an important place or building, you loose control of the camera and it moves to a very low angle looking up at the building. It makes your character feel small and the building feel big and intimidating. It is this sudden loss of control that I think is scary. You get these angles in the films but you don't feel the lack of control because you never had any control to begin with.
I saw all the films in the cinema because I enjoy seeing films on the big screen. Because I was in a room with a lot of other people, I did not feel scared because I was not alone. With the games however, I play them in a room by myself with the lights off. All my attention is on the game so when I get shocked, its amplified because I am alone and the controller is vibrating wildly.
The difference between the films and the games is the interaction the individual has with them. With the films, there is very little interaction. You sit there with everyone else and absorb what you see. With the games, you sit there and become immersed in the game. You are in control of the character and it is up to you to reach the end of the game. With the films, you always know that the character is going to succeed.