There are quite a lot of people started making video even film with gaming footage.
Youtube is one of the platform people uploading their video to.
There are many ways that you can do it. You can just simply record you gaming footage and combine them into a video or you can use some of the in game feature to make films.
One of the most popular game people making video with - Grand Theft Auto V
For example, Grand Theft Auto V is a game which have an in game feature called "Rockstar Editor" which allows you to control the details of the world to fulfil your requirement of your film. In this open world, you can easily make your favourite scenario for your film, it can be a car chase,a bank robbery or even a war! And the biggest advantage to use in game feature is - you can easily make realistic movie or film!
Of course, you can still use other game with no feature like this to make a video.
A software come with an Nvidia display card with screen recording feature - Geforce Experience
This way to make a video is less realistic compared to using in game feature to film because if you use screen recorder to film, you won't be able to control the in game world so that your content maybe a bit restricted. But you can still make great video by combining many gaming footage into one video.
This is the video from one of the popular YouTuber of his combined funny moments from different games.
After you record your footage, you can use one of the video editing software but that will be tricky if you have never use one of these before.
Adobe Premiere Pro - one of the professional video editing software
Windows Movie Maker - one of the movie editing software for beginners
After you edited your movie, you just have to publish your video to any of the video sharing platform like YouTube then you are all done!
Making video with gaming footage is becoming a trend since people can easily change their usual gaming footage into a video that easily attract huge number of audience.