It has an interesting setting very reminiscent of Xenogears that mixes Wildwest, Medieval Europe and Ancient China aesthetics which makes for a pretty rich backdrop full of colorfull characters.
Together with some TTGL esque comedy and a dash of CG over the top flare, due to sharing staff that worked in said series, you never get a dull moment.
I also really liked the Mech design, specially Muga and Gigan Reppu.
Overall I feel this show gets carried by 2 characters: Shu and Emperor Zetsu, since Back Arrow is mostly generic shonen mc material but the support cast is really strong as well and everyone gets a moment in the spotlight(specially Kai, Ren, Prax and Princess Fine).
A pretty great show in general, with some kickass action scenes and cool music to boot.
