The last show I reviewed, Powerbirds, is also a superhero cartoon for preschoolers. While that show is fine, I think Starbeam manages to top it in many ways.
Animation: The show is notably animated by the same studio who animated Ready Jet Go, which has beautiful animation, and while this show's animation doesn't resemble that of Ready Jet Go, it is good nonetheless. I like how expressive the characters are, and that their eyes and mouth are animated in 2D while the rest of their models are animated in 3D. My only complaint is that, why are the adults so tiny? They're so short, they're the same height as the children.
Writing: The writing is alright for what it is. It's smarter than your typical preschool fare, and I like that Zoey has a mantra to help her calm down, solve problems, and be confident. I also like that Zoey is a rare female Asian superhero in a show for preschoolers, good diversity.
Characters: Zoey is a great role model, she's not perfect by any stretch of the imagination, but she's really likable and relatable as she struggles to balance school with saving the day as Starbeam. Henry is a supportive friend to Zoey. Zoey's mom and grandpa are also supportive, wise, and have their own quirks. The villains are believable, especially Miserable Marla in the picture day episode. What happened to Zoey's dad, though?
Music: I can't remember much of the background music, the theme song is really catchy and fits the tone of the show well.
Enjoyment: The show overall is really fun, sweet, and wholesome, and it has great lessons. It could be better if it did a commentary on cheesy superhero shows of the 60s like Powerbirds, or maybe even introduced a story arc like Chip and Potato, but I guess it's fine as is. I recommend it.