I was talking about the Mac version in Shapeshifter, which needs a 640x480 screen to run, like many Mac games. Even if you choose a low resolution with a 640x480 screen (Pal/NTSC Low Res for example) reduce the window size, and centre the screen by holding the left Amiga key and dragging the screen into position it's still unplayable on a 030. However, doing the same thing with Dark Forces makes it playable on the 030. This is with AGA, I don't know how either of them run with a graphics card or through Graffiti.
I know because I have tested all of this on my real Amiga hardware recently.