There seems to be an input bug on Cap32 (amstrad) core on the s905. There seems to be no joystick control or limited anyway. The core options have been enabled for retropad and amstrad joystick but no control. I do have it working by using the Cap32 core from RPI builds so its fully playable with joystick control on the s905.
The other amstard core crocods works fine on s905 although a bit buggy at times.