It is possible to use gameport joysticks/pads on amiga, but if memory serves me correctly you need to use newlowlevel.lib as opposed to "normal" lowlevel.lib. Additionally I think it can only be used with openpci sb driver. Once its set up though it should work fine with anything that typically can use lowlevel.lib.
Sorry for the vagueness of the response, its been a while and my memory is a little foggy
