Hi Sparky-D, first of all thank you so much for the comment and compliments. There is actually a difference in the control mechanism between the original version and the plus version.
In the original version, by leaving the joystick in the same direction, the character moves in the indicated direction as if joystick were moved repeatedly. On the contrary, in the plus version the system waits for the finger to lift from the button from the keyboard or the the joystick come back to the original position.
The ugBASIC language, being isomorphic, does not present an abstraction for the input and therefore gives direct access to the I/O subsystem. Wanting to write a single source, I therefore opted for this different approach by virtue of the numerous, and differentiated, input methods present on the various computers.
Fixing the problem shouldn't be difficult, and it will definitely be one of the improvements in the next version. Since I would like to stay on the single source valid for all computers, a certain period of testing will certainly be necessary. As soon as the new version is ready, I will update it on this page.
Thank you again for the suggestion, and have fun!