Oh Sawa is playing the Earth Defense Force game. That game has been shilled by one Japanese dude for months. I remember his superchats that he sent to Phase last year, and I recently saw him again. I thought it was a meme but apparently it's a real game.
https://www.youtube.com/watch?v=vVB1jJq7xNQhttps://www.youtube.com/watch?v=vVB1jJq7xNQhttps://www.youtube.com/watch?v=vVB1jJq7xNQ