Few tips
Your drawings look pretty good uncolored. But You need to definately add some color then shading on top. As for your trailer I like seeing your graphics but hated seeming them fade in and out at probably what 12 or 10 fps? First thing you gotta do is add in a much higher fps. Most people use 24 or 30. I use 30 when I use sprites and 24 for mouse drawn movies. Also when you make trailers you wanna have a catchy song and a little bit of story in it. I saw no plot and J-pop isn't exactly going to make 90% of newgrounds wanna watch this. Just words of advice for you, I know you can improve you got potential.