Don't Leave Me Alone, Daisy

It's a pretty cute, though somewhat naive anime in which most of the characters are hyperbolized. It has robots and mutants, and travels through space and time. However, the main character looks like a maniac: he kidnaps a girl, keeps her chained up, conducts experiments, so the love line is similar to Stockholm syndrome, so if you take what is happening too seriously, it's better not to watch.