Here's a summary of it:
Star Trek Voyager: Tattoo
Many years later, Voyager finds a planet where the same native American symbols appear, and which throws up a storm every time they try to land or beam down. Then some people with Chakotay’s tattoo turn up. It turns out they are the Sky Spirits, they’re real, they’re aliens and this is where they live. Oh yes, we also find out why Chakotay got his tattoo, to honour his father after he died. This is also why he joined the Maquis. The trouble is, he just tells us all this, without it really having any impact on the plot, such as it is.
The first two reviews touch upon perhaps the most serious problem, which happens when Chakotay meets the alien "Sky Spirits." Memory Alpha describes the scene:
The humans lacked language and culture until the aliens gave them the "gift." This also instilled "creativity and a spirit of adventure" in the humans, leading them to cross the planet and eventually to populate the Western Hemisphere. The SF Debris video review explains:
Nor was this "message" some sort of thoughtless mistake. As Memory Alpha notes, the writer explicitly intended it:
Tattoo has other problems besides the racist "ancient astronauts" and the lack of cultural specificity:
Okay, but when they find their relatives, these people all have nose ridges like the alien Sky Spirits. Why? Did the aliens impregnate the Indians? Why doesn't Chakotay's group have the nose ridges if they share a common ancestor? And why doesn't anyone comment on this issue? "Hey, these Indians look unnatural. Has anyone tested them? If they have alien DNA, the Sky Spirits must've been real, not a legend."
Some reviewers consider Tattoo a decent episode, even above average. I'd say it's bad. In particular, the Native aspects are handled poorly, at best. Only the subplot about the Doctor's infecting himself keeps the episode from being a complete loss.
For more on the subject, see Star Trek Voyager: Chakotay.