The semantics of real continuations are less trivial than that, and they appear (to me, at least) substantially more convoluted when applied to procedural, as opposed to functional languages. What you're describing is still a form of generators, which can be built with continuations and anonymous subs, but doesn't provide the full power of continuations.
Additionaly, rebinding @_ is most likely a bad idea. There are better ways to pass values through to continuations. Changing your local context somewhat defeats the purpose of continuations to begin with.
s aamecha.s a..a\u$&owag.print