Good enough grammar, it's actually readable, so that's a plus. Updates come out pretty frequently. The pacing of the story is a bit quick, but that's better than spending fifty+ chapters on the first year of childhood like some authors tend to do.
The character design falls a bit flat for me. Gonna be honest, the MC doesn't seem like he has an actual personality beyond bland, nice guy, everyman. It's not that bad, but it isn't anything great, or even good. Just kind of a meh protagonist. Kind of like that dude from In Another World With my Smartphone.
The world background is the part of this that actually bothers me. Like, the dude gets a Demon System, and it would be interesting to see how a relatively normal, goodish guy handled a system that rewarded horrible behavior. Trying to find a balance between being a monster, and keeping your morals in the face of ever increasing rewards would be an interesting plot point, or it would be if the author wrote that story.
Instead, the Demon system seems to pander to the protagonist in ways that really, really don't seem even remotely demonic. Like, he gets sin points, not by killing anyone (though he can and chooses not to), but by beating up child bullies and having them confess their sins, or by catching a thief. Basically, the "Demon" gathers "Sin Points" by doing good deeds. It is a mechanic that shouldn't bother me, but it really, really does.
