==getting more buttons==
As Amstrad CPC does sport only one Joystick connector, but it is theorically possible yet a simple montage allows to customise some kind of 6 buttons Joystick quite easily, if only softwares supported thisdispatch 2 joysticks on the same connector.
The Plus range features this internally. But as a result it is theorically possible to customise some kind of 6+ buttons Joystick quite easily, if only softwares would support this. *Simplest way : using the 4 directions of the second Joystick (on a plus or using a Y-double connector/cable on a CPC) as additionnal fire, for use in 1 player games, you then put one joypad in each hand (the "nunchaku" technic).
*Meaner way : re-cable a modern joystick/paddle/game controller sporting a shitton of buttons...a Playstation gamepad may be re-wired a such to allows a total of easily 10or12 buttons
Such a custom device would need 2 controllers connectors to be used on an Amstrad plus, but may be implemented directly for a CPC (old) usage.
==Finding proper joysticks==