This episode does a wonderful job establishing the hero and villain of the show to come. The training scenes where a young Jack learns to become a stealthy samurai are very engaging and are able to tell the story really well with pretty much no dialogue. When he becomes the samurai that we know and love, he is someone you don't want to mess with.
The opening scene of the episode that shows Aku escaping from his imprisonment is very effective and chilling. He is an amazing villain who is obviously very threatening and would go on to have many encounters with Jack later in the series.
The movie also does a good job with its world-building. The animation and scenery in ancient Japan was really beautiful and set the mood nicely. The world many years in the future that Aku throws Jack into is given a good introduction and is established as a place where Jack is in way over his head.
The action scenes are fantastic as well. The showdown between Jack and Aku before Jack gets sent into the future is pretty impressive, and the battle at the end where Jack takes down an entire robotic beetle army is all kinds of epic.
If I had any complaints, it would be that the scene at the bar where Jack talks with the dogs was a kind of slow and took me out of the movie for just a little bit.
Overall, this was an awesome movie that started off this amazing animated series right. If you haven't seen the show yet, it would be good to start here.