Most Excellent Adventure, to my knowledge is a free time-travel RPG based on Bill and Ted's Most Excellent Adventure.
To my recollection, the only copy available was hosted on 1d4chan. However that is now down, and I don't know where else it's hosted. Googling hasn't turned up anything for me the last time I looked.
This is not the same as TimeWatch.
The dice mechanic relied on dialling a number based on the roll on your dice pool, and featured this diagram
I have found a potentially unsafe pdf hosted on
i.4pcdn.org (visit at your own risk). It looks exactly like the game I remember, but without knowing who is hosting it, if the PDF is safe and confirming it's the whole pdf I'm not confident it's the exact game.
Finding out who made the game, would go a long way into making sure it was the right game and that it was a safe copy.