A few ST games were never released on Amiga, notably these two. Also, it turns out there are loads of ST emulators for Amiga that I sort of suspected but didn't know existed, even though I had tried a Spectrum and PC/DOS emulator back in the day.
So, for no reason other than in case someone else also happened to miss it, here's
Meynaf's site that has these games and a
generic search link.