My only experience in video game RP is the Habbo Hotel.ca RP's that used to exists and a Halo 3 Custom Game a friend made that was essentially a hugely expanded version of cops and robbers. Pretty sure I still have the map for it too...

Anyways, what you feel is completely natural.
Game's require at the moment/real time reactions, you need be quick on your feet and quick thinking to do well in such an environment.
While with forum RP's you have the time to sit down, clear your head and invest your time into a decent high quality post. 

I'm largely the same way when it comes to playing strategy video games, I largely prefer the per turn ones where you plan each turn out rather than having to fight in real time.