I never had a problem with the giant monkey head robot, but I always thought it would be cooler (and fit in better) if the giant monkey came out of the ground as a full skeleton, and then the voodoo magic caused it's boney body (and head) to be encased in metal.
And I liked Jambalya Island's touristy atmosphere because it continued the Disneyland connection
that all of the Monkey Island games have had.
I'm also not worried about the apparent retcon in regards to Herman, because I don't think it is a true retcon. I still think Elaine was cursed (by the Voodoo Lady, LeChuck, or both) to believe what they wanted her to think. She accepted Herman too readily and left the governorship on Melee Island too easily. Plus, I never thought Herman or the Voodoo Lady were as benevolent as they seemed.
I didn't like Monkey Kombat though.