Read the web novel and some of the manhwa. I enjoyed the first arcs but it really fell off in the second half. Lost sight of what made it good. Not to mention the racism later on (heard the manhwa fixed this but I haven't read that far).
Having read just last week the 173 or so chapters available online (and just bought the two volumes published for my 12yr old, he loves it)... Nothing really jumped to me as racist, so maybe it was changed?
I know making an early vilain Japanese was seen as controversial, but (in the version I read) there was nothing specificly tied to being Japanese ergo bad there. It was just one bad guy with a devious plan.
I think what works so well here is the quality of the art (for monsters/ characters, the environments and vehicles can be quite slap/ dash. But of course this is a weekly color webcomic) and the color useage.
The sense of movement and the cg effects are also very strong.
Also, it's rather refreshing that the hero's actions make sense in context, and that the whole videogamification reason (levels, skills, menu, etc) given recently also makes a lot of sense - again in context.
Big points from me for not sexualizing the women too, though the few portrayed are very much in the background so far.