It is a cartoon movie or series. A guy finds himself in a room and realises he has to fight for his survival in a virtual reality game. The only person to get back to normal life is the winner. Players have to earn points. They have various kinds of weapon. In one of the scenes the guy is in a robot and is controlling it.
A friend of mine watched it 3-4 years ago. It’s not an anime.
Was it one of the stories from Love, Death and Robots maybe?
Or sounds like something from Black Mirror