Gaming

The act of playing a game in a PC or console (mobile doesn't count lol), usually in a serious or professional manner, as gaming is more likely the word to define full concentration or competitiveness on the act of playing games.

Practically unrelated example:

–Mom: Billy, come on, your dinner's gonna get cold!!
–Son: I'm still *GAMING*, mom! Let me alone!!
–Mom: Just pause it and you continue later, or I'll go up and turn it off for you!!
–Son: This shit's online, you can't pause it, dumbass!!!
–Mom: BILLY!!! *proceeds to go stairs up loudly*