I don't know a lot about Sonic. I was a Nintendo kid when growing up so played Sonic a couple times at friends houses but that was it. I am aware of the lore that's grown around it and the concerns of people who've followed Sonic and friends throughout the games.
When a company continues a franchise there's always a concern about whether they will be treating the characters and story with the reverence due to them. Sonic Boom tosses all of that out the window and it is all the better for it.
The characters are reduced to their basic personalities which is bad if you've watched them grow but great when you intend to have them bounce off each other in stories. So Sonic is arrogant, Tails is brainy and good natured if a bit naive, Knuckles is a strong dimwit, Amy is conscientious, and Sticks is a paranoid anarchic lunatic. Dr. Eggman is a villain but more of a needy overblown weekly threat bully instead of an existential.
These characters combine together to work through standard sitcom plots. It's not an adventure show and I feel that's why many reviewers are disappointed. Sonic Boom has answered the age-old question "So you want a realistic down-to-earth show that's completely off the wall and swarming with magic robots?". One episode is about Tails in love with a girl with his friends in the giving advice on how to approach her while Dr. Eggman is in the background trying to pickup a courier package but continually missing the delivery. Another is about Dr. Eggman assembling a group of villains to attack Sonic and to train they go through a series of team building exercises while Sonic and friends try and fail to build a piece of off-brand IKEA furniture.
The animation is bright, colourful, and expressive. It don't showcase amazing setpiece battles and there's never a huge amount of stuff happening on screen but I'm pretty sure that they're limited by their budget. It would be nice if they could hire an action director to help. I don't really care if sonic's arms are blue or not, if he looks off-model it's still good. (Take that Sonic fans!)
Finally, there's the absolutely stellar writing. the plots are clichéd and hackneyed because you've seen them on every cartoon and sitcom before, the writing is aware of this and highlights tropes while continuing on with the story. It's a neat high-wire act, simultaneously charging ahead with a story while pointing out how ridiculous the situation is. There are jokes about the mundane aspects of everyday life. There are jokes with a specificity that kids shows normally don't bother with, it isn't enough that Dr. Eggman has an octopusbot that Sonic mistakes as a squidbot, Dr. Eggman points out the relative size of the head to the tentacles making it clear what animal it is.
This decade is a time of truly great cartoons, Bojack Horseman, Rick & Morty, Archer, Adventure Time, Legend of Korra, and others. Sonic Boom skews younger with it's bright colours but the writing really does put it up there. The second season seems to pretty good as well with a parody of Misery so I would encourage you to check it out.
