Thanks so much for playing it! I'm not sure what happened in that Movement and Combat demo, but that one doesn't have an exit confirmation, so maybe you accidentally hit escape? I recall there is also an issue where you cannot jump when an item is "selected" in your inventory - I think it's fixed in the latest demo but I'll double check :D
For the Level Generation, the key was a bit of a last-minute addition so I definitely need to refine that. I'm trying not to add any extra "UI" elements as I don't want to distract from the atmosphere, but I'll have a think about how to improve the key's discoverability. Thank you for the feedback!