Second fail related to Wonder Woman

I tried to do a second time a Wonder Woman in perler beads, you know, ending with the ironing the result.  Here is what it look like once the beads assembled:

Again, my problem started with the ironing.  This time, I let the iron heat nice and hot.  I don't know if it is a big project the problem but I had problem fusing all the beads.  Maybe I should try the ironing with another method for fusion the beads.   Here are the results after the ironing:

So, now, I am a bit at a loss.  I am not sure of what I did wrong.  On the other hand, I was a bit more successful than the first try.  I got more bead fused than the first try.  So, I guess the heat of the iron was better this time.  I am just bugged on the small thing that I seems to miss.  I must investigate more to get a better conclusion on this project.