Detail level of textures is appropriate for a PC or console game
Blending is fine
Animation and timing is very floaty and linear
- the skulls could zoom up, hover then SMASH him in the chest
Needs some smaller bits of stuff mixed into the explosions - debris, sparks, glowy bits, cells, etc.
Skulls need some sort of effect around them
Colours should be in a smaller palette - that blue smoke should have all other colours tied to it. Effect on his chest is a rainbow of colours.
Good start but I would push it much farther