I can see that this is just an experiment which is totally fine, I just wanted to say a couple of things. I personally really like these kinds of animations, but I've done some stuff in animation too and I know how hard it can be hard to find a balance between rushing the animation and drawing out a scene. The moments are just too short and too jarring. Like when the black hole or whatever opens up and Sonic falls down, that moment should be extended to like 2 seconds to make it seem like he had to recover from it and to make the scene less jarring. And obviously this can be excused because this is just an experiment but scenes have to have explanation, they can't just happen. Like why are Sonic and Metal Sonic fighting, why did Mario show up, what are they doing when they jump into a black hole and come out into the same scene just slightly darker. Like I said, this is easily excused it's just for the future. Another thing that helps me when animating is to try and watch your animation as if your seeing it for the first time. You shouldn't have to watch the animation multiple times to understand what is going on, it should be slow enough and have enough down time to let you comprehend it on your first watch. One last thing that can be easily excused as well is the sound. Your gonna want more complex and unique sounds in your actual projects, and the audio you do have is to fast and loud to improve the video. The audio you have now is going by really fast and some bits are really loud so they can make it more annoying than make it better. Specifically the sound that sonic makes when he spin dashes in like the first second hurts my ears, it so high pitched and is so fast that it's weird, it's not even a sound effect, it's just a noise. The other sound is the one Metal Sonic makes when he dies, it's just so much louder and abrupt than all the other noises. Well, that's all I have to say about this, I hope you don't hate me now, I didn't really point out the good things you did because I don't really have time, I just wanted to tell you some of the big things I noticed that could be improved on. Keep working hard and I'm sure you will get better. I look forward to seeing you on the front page some day! Happy Suffering! Oh I mean animating...