Is science used to create video games

Yes, of course! Technology is part science!
If you want to create a video by yourself I recommend a pretty record tool - PCHand Screen Recorder which I'm using now.
It could record any activities on the screen and the audio of whatever you hear, even the left and right mouse clicks and mouse highlights can be recorded to be displayed in your recordings.
I find out about it from my friend and I tried it before I bought it. It's pretty easy to use. There is also a free trial version. I'm using it and it's pretty good…Hope it could help!