You're quite skilled at story telling. I just picked a chapter at random and could enjoy it on it's own merit. There's never too much exposition, and the story itself is clear, character-driven, and intriguing enough to make you want to keep on reading.
Pacing is good too.
As for the characters, Nico's reflex for self-sacrificing gestures is interesting, and I really like the slime girl. Emid is well written, but I've seen characters like him before too many times, so you'll have to work hard to make him distinctive.
Art-wise, the design of the three mains works really well. The comedy scenes are also well done. Action stuff needs some work. (I'm not a good artist myself, so my advice here is kinda vague on purpose)
All in all, this is a solid start, and could turn into something great. I'll be reading.