I remember watching this cartoon as a kid when the first episode came out. It started off weak at first, but as it progressed it had a well-developed storyline with memorable characters and cool fighting moments. Although you cannot travel back in time and undo everything for real, I declare it as a solid story.
This show takes on the adventures of a nameless samurai warrior who was sent into the future by a demonic wizard so that his reign can prosper. While initially the samurai is nameless, the residents in the future came to call him "Jack". It is a highly adventurous and action packed show that would be fun to watch for the kids 10 and up. For a cartoon, I got to say this is one of my favorites up there with Kappa Mikey. Samurai Jack himself exhibits the characteristics of a stoic hero. He is unfailingly polite and humble despite the completely alien nature of the futuristic world and never scoffs at or disparages the customs of the people he encounters (as unpleasant as they seem to him at times). As any adventure for older kids, violence soon follows. For the most part the battles that he partakes in is to banish the monsters and evil robots that thrive in the futuristic world. Blood isn't really an issue because almost everyone and everything he fights is a robot. As for the living he generally knocks them out or disarms their weapons. An excellent cartoon for any adventure fan.
Jack is a pristine example of honor, honesty and hard work. A lot of film and story references younger viewers (and less film aware parents) will not get. Some of the violence may be too intense for some kids. The style is simple but emotions portrayed are not. Example: in one episode Jack enters a silent black and white spirit world to save the spirits/souls of a family captured by an evil entity. Not much dialogue but a lot if intense imagery.