I love competitive gaming of the MMORPG kind, ie. World of Warcraft and specially Elder Scrolls Online. For those who are not familiar, you join a Guild of players and compete either in PVE (against the environment, that is the system's computers) or PVP (against other players). You usually band together in platoons of 2 to 24 players all linked together by voice (mikes and phones) to follow orders from a leader, military style.
Each player specializes in a certain role, healer, tank, damage dealer, etc... The level of virtuosity of some players is incredible and can easily compare with piano technique. After all you are also using a keyboard, plus a mouse - but the kind of multi-buttons mice we use is akin to a second keyboard under the right hand. Some players also add pedals. I usually play a damage mage, focusing on "rotation" which is a set of repetitive moves that will deal out maximum DPS (damage per second) using various chained techniques, and which I compare to arpeggios.
The key difference is that you cannot simply follow the score. You have to be ready at every split second to respond to enemy action. When I play the piano my technique is usually on auto-pilot (for a well-rehearsed piece) and my conscious control is geared to applying extra "feeling" or "touch", an artistic endeavour that is absent in MMO's. My conscious control is geared to avoid death!
I started on games late in life, as on the piano. My guildmates call me old-timer. But when a plucky 15-year old marvels at my DPS numbers, I tell him : "Well, I play the piano".