Rise, oh, where to begin?
To begin: the gorgeous animation and the fighting choreography are just amazing, as well as the fresh new take on the turtles' origin story, the worldbuilding and lore, and the cast's characterization, and I say this in 20+ years of being a TMNT fan.
Rise of the TMNT is truly a special, amazing, and inspiring work, made with passion and genuine love for the franchise. The jokes are funny, the characters are lovable, and the designs are original and well-fitting with each character's personality: from Leo's sharp wits and cunning to Raph's unmatched strength. I also love that the turtles are so widely different in species and design, and aren't the same model copied over and over with only slight color changes.
While I agree it starts a little slow, it still introduces hints pointing to a much larger lore and story, creating a world unlike anything we've seen before, yet lovingly and playfully referencing previous iterations.
As a show, it's action-packed yet wholesome, special in its own way. A real treat for all animation fans and would-be creatives. Strongly recommended!