I did a few pixel arts back in the day (and a lot in my most recent Splatoon 2 artworks).
Tip: I see you enlarged the character in the picture (at least I'm very sure you did), it's a lot easier if you just keep the original size and draw on that size instead so you can just use a 1px pencil to draw/color and keep a consistent line size + pixel art (especially maplestory related) looks better if you keep the original size.
It looks really nice though, I think it may look even better on the original character size!
Good luck! Enjoy some spaghetti with meat sauce and garlic bread!