Hi, I downloaded 1.1b and played it on a real 64 (1983 Breadbin) and Bub/Bob jump constantly, no matter whether there's a joystick connected.
Viewing post in Bubble Bobble C64 Remastered comments
⚠️ Two-Button Control & SID Compatibility on Real Hardware
The Commodore 64 relies on the SID chip to read the paddle inputs. The second joystick button is wired to pin 9 and is detected via the POT X signal.
If you experience issues with the second button, your system is likely using a SID replacement (such as SwinSID or similar) that is not fully compatible with the original SID’s handling of paddle inputs.
This is not a bug in the game. Any C64 software that reads the second joystick button through POT inputs will exhibit the same behavior on such hardware.
For proper control functionality, an original SID or a fully compatible replacement is recommended.
do other 2-button enabled games work correctly on your system ? Please try anything from this page and let me know https://github.com/crystalct/5plusbuttonsJoystick