Must brogue 1.6 be completed in one sitting?

I've seen there is a way to suspend the game, but after doing it and quitting, when I start the game again, I start with lvl1 on a new map, and I don't see any option for loading the game in any menu. I've searched the user manual and the forum and could not find the slightest hint how to load a "saved" game. I found the file .broguesave, but what can I do with it? Starting the program with it as a command line argument does nothing.

No, you don't need to complete it in one sitting.

To load a saved game, use the Open command in-game. It'll prompt you to type out the name of the saved game. It may take some time to load, and naturally the run you "started" will be obliterated, but you weren't intending to make that run anyway, neh?

On the same note, this is also how you access recordings - by doing it in-game. They are Viewed in the same way by specifying the name of the replay file.