I found 'metroid' in new version of demo. And I'm afraid
this gonna be 'serious copyright problem'.
As you can see, that's definitely 'metroid'. And it's too blatant plagiarism to be called an Easter egg or something.
Of course, I love this game & looking forward to meet the
full version. But, also I feared 'Nintendo' will never go
easy on you for this one.
I hate to say, but I think you should delete that 'thing'.