So, uh, I made a little rock smash script for fun. Obviously fat kid isn't in your party, and of course it's gonna ask if you want to use it, and of course it's gonna check if you have a flag.
https://www.dropbox.com/s/qab3xl9elk4xkww/Fat Kid Cry.AVI?dl=0 (watch with audio ^__^)
I can't help but feel a piece of technology would be more applicable for HM use - especially in this case. It's been stated before that technology is the focus, so avoiding the ~fat joke~ here and giving him something to reflect his personality might work better.
I really like your inclusion of previous incarnations of this character in your prologue - at first I was confused if they were screenshots or not, which I think is proof that you've done well! XD Your tileset also looks pretty nice, although the mountain-to-water tiles shown in the gif look like they might need editing? They look a bit muddy at the bottom. Idk.