Awesome!! But, even though it works for games, the timing overall is too fast. When I watch in quicktime and then adjust the playback speed to almost 1/2 (so maybe 30-40% slower), it feels much better.
The section between x10 and 20 is really cool.
How he hangs on around x40 is cool too.
The flip is neat idea.
Now, the hit around x100 is too fast, especially the creature's forward movement, it looses any sense of weight.
It's nice how he pushes the creature away around x180, but from x182 to 192 he's totally off balance. You need to move his right leg to the left like on x195 much sooner so he stabilizes himself. Once you do it earlier, you might have to add another step.
The creature specifically:
the pose on x37 is a bit odd, with the legs back and the hips forward, I'd rotate the hips down a bit more and move them back, because right now the move from x37 to 43 feels unnatural and ends abruptly on x43. The momentum of such a move would have the creature slow into the stop, the weight distribution would be cleaner.
From x63 to around 68 it's too pose to pose, plus the pose on 68+ is awkward. Is the creature trying to grab the guy, hence the "wrist clap"? If so, good idea, but make it clearer. Look at the silhouette on x68. Squint your eyes and you won't be able to tell where the hands are. The upper part with the chest, head, arms and hands is one big block.
The body move up from x87 to 91 is too fast and again stops too abruptly. All that mass will come to a rest in a slower fashion. This will get fixed once you slow everything down (as mentioned above).
From x126 to 136 the arm up move feels a bit odd and unmotivated, I think you could add a stronger pose to that. And then how it relaxes to x172 could work idea wise (agony filled spasms) but right now it feels like spliney keys from A to B, with no real purposeful timing.
His fall is cool, but it feels that the creature sticks on x187, I'd add more sliding and complexity.
That's it. All in all, really cool start!