In the first one the run was...over drawn. He floated in the air for MUCH to long.
The particles were different...maybe try having them break up into pieces, instead of keeping them all in little individual chunks that jsut get smaller.
There was some resizing in the second one, but pretty unnoticable. The punch was decent, but would be hard to follow up with another attack. Also the explosion lacked force. Try using less frames for the initial expansion, then dissapate the particles VERY slowly.
The blastoff really needs more force, maybe have him move faster or show more anticipation. Your particles are good, but they can be a lot better. Keep working on it, you could be pretty good!
Right now, I'd say med/high Beginner.