The characters are extremely two dimensional. All of them seem to use a short wordbank of phrases, are obsessed with achieving only one thing each and the lack of personality fail to make the characters come to life. Each individual character is not fleshed out in a way that you can gain an attachment and the side characters feel more like story filler than anything else. The character who shows the most personality and change in the show is Hitomi but given how the story flows, the character growth doesn't feel right.
The anime though has nice artwork. It's nothing mindblowing or over detailed but it is pleasing to the eye and simple. All the bodies are in good proportion which can sometimes be hard to find in a shonen.
