I've had no luck with it so far either, so I'm keen to hear what others say too.
I'm using a Thrustmaster T.16000M, if it makes any difference. The GOG releases of X-Wing and TIE Fighter seem to recognise it, but not this game.
EDIT: Worked it out. Once you've installed the game, just go into the Stunt Island folder, and open the Launch Settings shortcut. Go to Input device and switch it to Joystick. Then select 'install with the above configuration' and it will tell you to type 'stunt' to launch. Do that, and it will start the game and give you a joystick calibration screen. If you're planning to change the number of cycles Dosbox is using for whatever reason, do it before this calibration.
You'll be able to use both joystick and mouse after that. If the joystick is pulling down to the bottom right of the screen, you've set the dosbox cycles too high for the calibration and will need to restart the game. Cntl+F11 and Cntrl+F12 puts the cycles up or down. Best done when dosbox is just a small window so that you can see the cycles number in the window bar up top. I think anywhere between 3000 to 9000 is about right.
You can bring up the calibration screen anytime with Alt-J. Alt-p brings up the preferences. Hope this helps.
Post edited October 25, 2018 by YaGramps