OK,
It appears we may have our first potential bug reports, related to running Mountain Panic without a joystick attached. 
I've collated the information below, and we'll update this topic as soon as we've made any progress. Our sincerest apologies if you're currently having problems running the game.
The workaround would appear to be plugging in a joystick, if you have one or - if you're making use of an emulator - use the slightly older version of B-Em, 2.1a (Windows, Linux).Sam.
Pitfall Jones wrote:
I've found the first bug - on a real bbc-b without a joystick connected the man moves up and left when you don't touch anything.
Unfortunately the SSD image doesn't seem to work with the RISC OS BBC emulators which is a shame ... depsite trying many things, the keys don't respond for some reason, [though] the game runs fine ... both the previous demos worked fine, so [Michael Foot, author of !BeebIT, a BBC Micro emulator for RISC OS] thinks something to do with the keyboard control must of been changed as that's the problem.
Garrettimus wrote:
I noticed something strange though. In spite of choosing keyboard (and redefining the keys), I can't play with it if my original Acorn (analog) joystick is connected. It only accepts joystick no matter what.
Original report.DaveM wrote:
I've been running it all week in Nottingham without any problems, though this was always with Joystick control.
At the Risc Os London show I don't have a joystick - so I was hoping to demo it with keys HOWEVER it doesn't appear to be possible to start the game using any of the keyboard presses (even if you redefine the keys). Just tried it under B-em and I appear to get the same problem.
Pitfall Jones wrote:
I've noticed a similar joystick bug running on a real BBC-B.
If you start the game by hitting return without a joystick connected then the keyboard works but the player always moves to the left and up when nothings being touched.
If you then connect a joystick then the joystick and the keyboard both work fine.
I'm guessing this is because when the joystick is not connected the adval() reading is either all min or all max - so the bug is the game is trying to read the joystick even when it is not selected.
Original report.Samwise wrote:
I've just tested with B-Em. It works perfectly in B-Em 2.1a, which is what I played it through with the first time ... but it doesn't in the absolute latest 2.2.

It won't let you start the game with RETURN. It doesn't appear to matter which model of BBC Micro is emulated - they all fail to start the game in v2.2.