Hello and thank you for using HCM. I carefully read your question and i understand your concern. I will try to give you my opinion.
There is no relationship between playing a videogame and a heart problem.
The only think that might explain what you feel is related with the emotion or
stress that you feel wile you play this game or the body position.
The pain might be related with a body position, it might be a musculus-sceletik pain that you feel each time you play.
It is possible that during the game, because of emotions you might experience a little
sinus tachycardia, that means that your heart beats over 100 beat for minute and you experience this like a heart discomfort, that ends immediately when you finish playng and you get relaxed again.
I think this is nothing serious. If it really bothers you, you can take a holter rhythm monitoring that can register your heart during this episodes. After this we can better understand what is it and what to do.
Hope I was helpful. Best regards.