The phrase "poor character development" refers to a lack of depth or complexity in the portrayal of a character within a story or narrative. Full definition
I criticized the second and fourth movies for having poor character development compared to the first movie. (paulstriptothemovies.com)
From poor character development to cliche - ridden dialogue — those representing the legal system perhaps bearing the brunt (Naomie Harris is simply wasted)-- the film won't do much, if anything at all, for those with concerns of it being «just another boxing movie.» (digitalshortbread.com)
It's poorly written with a terrible plot and poor character development. (relevantmagazine.com)