I don't mind that you don't have different sigils for scalars, arrays and hashes (the number of characters is rather restricted compared to the number of different types you might want to distinguish like that), what I do mind is that there are no sigils at all which combined with the fact that you CAN'T declare variables is rather ... nice.
In Perl I can say HEY DUDE THIS IS A NEW VARIABLE no matter what variables exist elsewhere. In Ruby you can't and the usual response of faithful Rubyists is that it doesn't matter because all methods should be at most up to five lines anyway. Which 1. is not always possible and 2. forces you to be very inventive when nameing them. Plus due to the missing sigil it's not just variables that can clash. So you may define something several months later several pages away and voila, your local variable is no longer local variable. If you are lucky it's not a variable at all and you use it in some way that'll cause a syntax error. Oh, I forgot, you are supposed to have tests for everything so nothing bad can happen anyway right? I don't need the seatbelts, I'm a good driver, right?