I'm a dumb end-user, but here are my thoughts anyway.

Doesn't work, what am I missing? Wallpaper app works, so does hyperspin that starts mamehooker, but the script doesn't launch one after another.
What exactly is happening? Is the wallpaper app launching, but not Hyperspin?
If that's the case, it might be waiting for the one program to close before opening the next.
I'm not sure about ahk, but in a batch file you'd make it:
start wallpaper.exe
to run them simultaneously. (Run, start c:\wallpaper.exe marqeuee.bmp maybe?)
If the wallpaper app isn't launching, then will it launch if it's the only thing in the script? If not, then does it depend on something that loads with explorer and isn't being loaded when shelled?