Not sure if this was a crash or just the end of the demo, but when the first guard gets droned, the game seemed to freeze/crash when the option for the tutorial was selected.
Just loaded the save and it loaded without crashing, however, the UI or at least the health and such on the bottom right didn't load. After dying to the guard that entered, and loading from that screen, the UI displayed properly but it still crashed at the tutorial selection when selecting "Answer". Further testing, it crashes on both the "skip tutorial" option as well as "Answer". Will try on a different browser shortly.
Downloaded Chrome and it still crashed at the same spot. I don't know if it's relevant but the console shows this right when you select an option.
2index.js:459 res://Scenes/Dialogue Balloon/balloon.tscn
I dunno' if the "2" right before index.js:459 means it's trying to load the same thing twice, but it seemed like the only line in the console that showed that little number in a bubble just to the left of "index.js:459".
Best of luck with the bug squashing! Seems like a very fun game!