It's mainly the lack of personality!
I decided to overview the trailer countless times and looking at every model in the overworld in it....yeah they all feels so void of personality. I feel in anything Chibi (best example I can think of rn Megaman Powered Up) the importance of showing personality in characters is immense otherwise they look simplified and hallow. The npcs, barry, rownan, and especially the mc all fail in this aspect which mainly makes me dislike them. Also noticed how Rownan doesn't have his hands behind his back in the lake scene so these are kinda downgrades of the original style?