There is a bug in the serialization code for struts which can sometimes cause your plane to spawn underground, and prevents you from creating a new plane. I have fixed this bug, but can’t upload the fix until the rating period of the jam is over. For now, I would advice using struts sparingly.
If you do run in to this problem, you can fix it by deleting the PlayerPrefs file located which is located at:
Windows: %APPDATA%\Unity\WebPlayerPrefs
Mac OS X: ~/Library/Preferences/Unity/WebPlayerPrefs
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