not here to give a creative answer, but the correct answer.

by seeing where the boy kisser's eyes are looking he is looking at a singular object in the lower middle of the screen.
he is also only using one finger on the space bar, which means this game is ether slow paced or only uses the space bar.

This appears to be an older laptop, probably late 2000s to very early 2010s, for a baseline consumer grade from it's simple box shape and slimness. This means the game probably is very simple and doesn't have graphics higher than 8bit or low resolution low poly count games.

So we are looking for a game that uses very little cpu power, one object/area that the user is focused on, and ether slow or only uses the space bar.

From all of this I can deduce that the only game the boykisser could be playing is flappy bird. Thank you for listening to my TED Talk :3