ok,
after viewing all of your current episodes i'll leave my first review. first off, the voices, sora should've had a slightly higher pitched voice actor than the one he has now (he isnt his older self after all, he's still like 14 or something). Sly isnt too bad, a little off but he still sounded good regardless. as for ratchet, at certain points in the series he sounded really gay (no offense to the voice actor). Jak, well i havn't played the game for a while, but he sounded ok. as for Jack (your character) i cant criticize the voice, seeing as its yours. but you might want to put a little more energy into your acting, you kinda have a monotone voice on occasion. make your voice go higher or lower depending on the mood Jack is in. the same can be said about the others (though some of them already do). oh BTW, Riku's voice was too low, and Kairi's voice wasn't high enough, but it's too late for that i guess.
now for the animation, it's not all that bad, but could be better. you'll want to make your custom sprite animations a little more fluid; they're just too choppy. the background was nice. oh and since you're using MMZ edited sprites for most of your characters, maybe you should go back to using the sora sprites from the first one there's bound to be a larger sprite sheet out there than the one on spriters resource (or wherever you got them). where did you get all of the custom sprites for the other characters anyway? did you make them yourself? or was there a special website that had them. and i have one suggestion for your character's image, and it's kinda bugging me. the foot that points toward the audience makes it look like he's standing on the edge of a cliff with his toes over the edge. if you could fix that problem that would be great (at least for platform background and leave it as it is for overworld background.
the storyline is ok but you need to go into more detail with it (Jack tells everyone his friend's' names but doesn't explain how he knows them). the script could use some work too. some of the lines could be made simpler and more into character depending on who is saying it. i've played their games so many times that i know exactly how they would react to what someone (or something) says or does. for instance, Sly is a little more loose with how he talks, he isnt as serious as you are portraying him, Ratchet is the other way around, he can be serious when he has to be. as for Jak, if he wants to do something, he wont ask for permission, he'll do it by force if he has to, and he can get annoyed easily (but you've done that part already). if you need help with that you could always send me the lines for the characters. just let me know.
this series isn't half bad, but i feel like you haven't tapped into your full potential yet.
keep it up, and always try to outdo yourself.
P.S. i might even audition for a part in the show, if you can tell me how. just let me know via personal message if you need another voice actor. i'm a male BTW.