The crypt_password! method manipulates given.password, replacing its content with the return value of String#crypt.

So by the time the comparison happens, given.password will already contain the cryptographic hash.

Solved.

I can remove them, but I would label that as a suggestion, more than as an issue...

If you are no longer facing any trouble, you should mark this issue as resolved.
You can do that by replying to it and clicking on the appropriate box below the comment area.

color is supposed to be a variable, not a function.
And while choice of color is random, a single ghost can have only one color.
Using random color on each call to color function will make a singe ghost have multiple colors.

Also, when you are not really sure where the problem lies, a question is more appropriate than an issue.