I really like the idea, however, the gameplay just doesn't really create any kind of flow for me. Maybe it's because the player doesn't get enough time to get used to the mechanic. I think an issue is that the mechanic doesn't really ... "come to play" for me. I didn't get to use it in a clever way, and so it was rather just a pretty short and frustrating shmup for me.
But don't let my comment bring you down, like I said, I can see you put some thought into it, maybe with one or two tweaks, you can really make it good (even for me), and maybe others will find it very enjoyable! :-)