Found the way to get out. You need to crawl through the wall in a place, where the basement window located. Look at the screenshot

Hello,

Thank you for sending us your feedback regarding this issue.

Unfortunately, the problem regarding the broken stairs is a known issue that has previously been reported.

Closing as duplicate of #134.

Please upvote the original issue to increase visibility and feel free to add any extra information (updated repro steps/screenshots) in the notes section.

Thanks