In my testing, the game was able to be completed without issues, but unfortunately, the launch version encountered various problems that I did not detect during my own testing.
I have since implemented two fixes, which should resolve the black screen issue, as well as the problem with new train cars not spawning and the progression not being smooth.
Thank you for your understanding and patience. As an indie developer, it's incredibly difficult to catch every bug during testing, and I did not intentionally overlook these. I sincerely apologize.

If you encounter any other bugs, please send an email to [email protected].
All emails will be responded to. Thank you!