Lets be realistic.
First of all I would like to congratulate you for your achievements. Not only you managed to do a complete and honorable series, but you have developed skills in an incredibly fast way. I've seen all the castle series, and you do diserve some credit for it.
But let's be realistic. It is still STICK. I've seen better animations and I've seen better stories.
The whole "Castle" background is so out of context. It doesn't makes sense, even for a Fiction story.
Maybe it's because you wanted to make something out of your first movie, witch, I guess, was made to be just another meaningless "Stick Action Motion".
A good story must be created BEFORE you do the movies, not after.
NOW WHAT DO AMAZES ME!
THE SOUND EFFECTS AND THE VOICE ACTING AT REPERCUSSIONS. BOY, IT WAS THE BEST OF THE BEST. 10/10 FOR THAT.
So my point is, keep doing the great job on castle, you have many fans, but do a side project, use your creativity to bring up a new story, and bury the stick animation. Put some effort on it, draw non-vectorial background images, use the awesome sound build that you used on repercussions.
And maybe, MAYBE, you can stand along with Breckenwood Series - Tarboy - The Composer - Mastermind - Tankmen - Dare - ETC (The NG Immortals).
I really hope that you come to read this review and maybe reply it.
