There is a very old-skool platformer style game called Doukutsu Monogatari or Cave story. You can read more about it here. It has multiple endings but the main drawback is that it has very limited save support - there is only one save slot available - which is quite similar to another old-skool game ADOM.
But it doesn’t take a super-guru to right things for this one. Here is a quick-coded bash script which adds the capability for multiple saves. It’s based on the fact that the save progress is stored in file ~/Library/Preferences/com.nakiwo.Doukutsu.plist
What is done precisely is just saving the current file to a Save directory with a description supplied by the user.

Installation:
- Download doukutsu script here
- chmod +x doukutsu in case it’s not executable
- create a directory named Saves in the directory where you put doukutsu script
- you are done

The usage is straightforward, just follow the instructions when running the script.

P.S. It will locate the Cave Story .app file on its own if it has been put in /Applications folder