Its Local and each player needs their own controller, also player one has both keyboard and first controller, so you need at least two controllers, you might be able to use steam's remote play if playing on pc
I'm late to the party but I was wondering how does one do the noclip cheat on the switch as its not in the menu, I know you can type it in the PC version but hooking up a usb keyboard to my switch lite is a no go as the keyboard only works on the intro videos.
Seeing as I can only get it to crash with the automap open then yes, I can do more testing in the morning but I never had it crashed without the map so far. I do recall the map being bugged in the dos version as monsters can spawn outside the level but iirc you had to be playing for a very long time for that to happen.
Edit: After some more testing the game doesn't crash if I leave the game idle in the same spot with the automap closed.