This is a cover of the main theme music fanfare for the 1990 computer game Wing Commander, composed by Dave Govett and George Sanger. You can download a piano transcription here.
Although I am playing a keyboard, a piano is not the sound you hear, so allow me to explain my process for this cover. The whole thing took 3 days - 1 day to learn and transcribe the theme music, and 2 days to record and "orchestrate" it. I recorded the performance data live like you see in the video, I then went into my DAW and changed what the midi notes trigger to match orchestral samples. I tried not to add too much to the performance that wasn't already there, hence there aren't many "extra notes," just adjustments to midi lengths and some octave shifting. I think it's amazing how much of an orchestral sound you can capture with a piano performance. I'm mostly using Spitfire BML Mural. I could have done a better orchestration, but for the most part I wasn't doing much midi automation or adding extra rhythms, just orchestrating a performance.
The music to the Wing Commander games is all pretty good, I especially like some of the Wing Commander: Privateer stuff. These are great games, check them out if you haven't already! Of course George "The Fatman" Sanger is a legend in the video game music biz!