I've left it running for over a week, and the memory use gets to be Quite Big:

VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND                                                                       

23.0g  18.3g  17.9g R 162.3  58.4  35322:54 NQL.x86_64 

Memory used + reserved  - 23.0 GiB

Non-swapped actual physical memory used - 18.3 GiB

Most (17.9 GiB) of that is shared.. but it's still taking up over half of the RAM here, and these are way higher figures than at the start of running it.

I wondered if it was the log file being held in RAM, but that's 'only' 603 MB.

Haha! Yeah, while of course one doesn't deliberately introduce any memory leaks in a program... I have zero doubt that there are some. (Probably even some just built into the Unity engine.)

I definitely don't recommend running NeuraQuarium for more than a few days at a time without saving, quitting, and loading. Personally, I usually don't leave a single instance of the game open for more than 24 hours.

There was I thinking proper memory management was one of the points of C# :)

If there were command line options to say 'load this file, run this long, save and then quit', it'd be good :)

As it is, it's not easy to automate without something that can record and replay mouse clicks.