Yeah this is basically correct. There is nothing really preventing an elevator from reporting that it's going both up and down. The up/down indicators are used for two things:
1. To shut off the up/down request indicators correctly on the floor when the elevator arrives.
2. By passengers to decide whether to get on an elevator or not.
Developer here! Thanks for all the feedback. Appreciate all of it, including bug reports! Pull requests also welcome.
Especially I would appreciate help with adding more challenges, and/or making them all balanced and interesting, for a good and reasonable difficulty curve.
Yeah! Something I think about occasionally is traffic-light optimization problems, optimizing for throughput, wait-time, safety etc. I think it could work well in a packaging similar to Elevator Saga.
They spawn at a fixed rate, but at random floors, with 50% spawning at the bottom floor.
I agree it would be more interesting if there were patterns, distributions, more popular floors etc. Haven't gotten around to implementing it. There's a small unused bit of code here intended for this:
https://github.com/magwo/elevatorsaga/blob/master/challenges...
The additional-people-not-getting-on is kind of an architectural problem with the game, working on it.