What are you testing? If you said, maybe I could give more detailed advice.

Generally though,
– The character isn’t moved by any of the people jumping on him, it just looks like they’re balloons
– You need to translate the impact using screen shakes and recoil for each heavy attack
– Minor mistakes, the paper floats on his side, the elevator closes to the right
– The punch feels like a tap and has no weight, you gotta show something to give power
– There’s a little bit of jitteriness around here and there

Main problems are with weight and impact. You need to show that each movement has value, so the watcher can tell what’s goin’ on.