I went to Robot Restaurant the last time I was in Japan a couple years ago, and had a blast. But you’re right, the food is pretty bad – don’t make it a real dinner.
I will say, I got pretty bad food poisoning last time I was in Japan. Raw pork sashimi (I’m thinking that’s likely what it was)? Risky! I like it. I think the almost-raw chicken liver did me in, but I also did raw egg, beef, fish (obviously), so who knows…