Cliffhanger is an original arcade game for the Coco 1/2, with 3 levels (that I know of, and are mentioned in the instructions). In it, you have to get your picnic goodies at the top of each mountain; you can run to the right, jump straight up, or jump diagonally up and right. On the first level, you jump boulders coming down. On the second, you have to jump pot holes. On the 3rd, you have to jump snakes.
There is also a timer in the form of the tide coming in; the longer you wait, the higher the water rises, and you drown if it touches you.
Thanks to Ciaran Anscomb (of XRoar emulator fame, for pointing out that this game originally appeared over several issues of the UK magazine INPUT. This was a fixed run (52 issue) magazine to teach programming on a variety of computers, and Cliffhanger itself was listed for multiple platforms: Commodore 64, Dragon 32/64, Coco 1/2, . These issues, in their entirety, can be found on the Internet Archive (see issue numbers below).
Title: Cliffhanger
Author: S. Kelleway & G. Hedley; created by A. Doe
Publisher: Input Magazine (Vol. 3, issues 29-39 & Vol. 4, issues 40-49)
Released: 1985-1986
Requires: Color Computer 1/2/3, 16K RAM, cassette or disk.