Fun idea, but I kept getting words made up of non-English characters, which... Made it really hard, since those basically were unstoppable? I dunno. Maybe I missed something.
There are 2 words in japanese, so they are not supposed to come by very often. It's kind of a joke really, there's no way to stop those unless you have a japanese keyboard. Initially I was gonna have one of the power ups destroy all ships to use in this situation, but I had no time to do it >.<
Thanks for the feedback =)