You can get some interesting effects when your code goes off the rails:
V1.5 notes -- 2/6/2019
More work on the intro movie, have it more or less OK up through
the keypad scene.
V1.4 notes -- 1/28/2019
Added backgrounds for the intro movie.
Can now trigger the beast animation. Slugs appear on ceiling but
cannot fall yet.
V1.3 notes -- 1/21/2019
Added slugs to second cavern room. Can climb slope in rope room now.
V1.2 notes -- 1/20/2019
Added more of the rooms. Started making the code generic so I can
arbitrarily turn on earthquakes in any of the rooms. It's beginning
to look like I might get around to implementing much of the game up
to the first checkpoint.
V1.1 notes -- 1/19/2019
Had thought I was done, but no, I went and added another room
(the rope room to the left of the pool). Still need to enable earthquakes
for it (and of course, eventually, rope activities).