The quality of the pictures overall is low, the plotline needs deepening. YOu don't just walk up to a random stranger off the street and start a journey together. Dispose of the white spots around the sprites. Most sprites don't look good when you take the editing tool and flip it, so either scratch or take out the Ash laying down part. Did you use the spray Can tool to make clouds? It shouldn't be used for spriting. USe the line tool to seperate the different parts, a crooked line doesn't look right. On the dialouge, you shouldn't leave off letters, and start off on the next line. Just do it all on the same line. Wouldn't having Jessie and James as hosts either place them in an alternate timeline that the pictures take place? Or at least the future. If the future, you should edit their sprites, but thats for continuity, meh. You shouls just find the drass spre and do it overworld-ish, it'll make the comic better.
But stuff like that is just me, so...