Good start, needs improvement
You're off to a very good start, but improvement is needed. I thought the graphics were pretty poor, but as I know from experiance you will get much better at this in the future and I honestly hope you do. The background drawings didn't match the character models at all either, the bathroom looked like you doodled it in about 3 seconds. I'd suggest taking more time on the backgrounds. On to the animation..... A good start you know how to tween which is a great start, but I think with future installments you should have alot more movement. You need to do more than move a hand here and there. Put some emotion into the animation, move the head, actually lip sync your voice overs instead of the 3 frame movement you have right now(sub-zero and scorpions mouthmovents are fine I must say), I'm speaking of the "non ninjas". The audio was decent, there weren't any clicks and noticable breathing in the mic which is always a plus. Kudos on the audio. Voice acting was also decent although there wasn't much emotion. Emotion in the acting always keeps the audience awake. I say this because I found myself a little bored at certain parts. I love the idea for the cartoon. I could see this series becoming brilliant if you keep improving. I wish you the best of luck with future flashes.