The movie opens on a group of teenage friends, competing in a 1982 video arcade challenge. Footage of the contest is launched into space. In the modern day, Adam Sandler is the contest runner-up, now an in-home technology installer. He's shortly called to the White House because one of his friends is now the President (Kevin James) - and the world is being attacked by characters from those video games they used to play. They assemble a group of aging nerds (those who know the games in question) to fight off the invasion.
This was never going to be a great movie, but it had the potential to be a lot of fun. But as directed by Chris Columbus, written by him and Adam Sandler, and starring the trifecta of unfunny, Sandler, Kevin James, and Josh Gad ... it wasn't to be. There are a few gags that raise a smile, but many more are dead on arrival, or cause a cringe. As an example of the peak of their humour: the aliens sent their messages to Earth by repurposing 80s and 90s TV broadcasts, so messages of invasion were delivered by (among others) Ricardo Montalbán and Hervé Villechaize, and Hall and Oates. That was worth a grin, but now I've spoiled a couple of the funniest moments in the film for you. The rest were dropped in the trailer.
This movie is very much about my generation of video games, the stuff I grew up playing. I'll stick with that excuse, and the COVID-19 boredom as to why I watched this. Trust me, there's better stuff available - no matter how bored you are. Perhaps you should go watch the 2010 short by Patrick Jean, also called "Pixels" (it's available on YouTube), which inspired the movie. Or play some of those old games - either would be time better spent.