GOOD GAME. Music & SFX are on point. Gameplay is SOLID. I didn't see the point of focus mode. My only complaint is the camera zoom as you approach the center is kinda annoying--feels like I lose a lot of stage awareness because of it. Everyone else is talking about circling being a viable strategy but I think they're missing an important point--just circling will keep you from dying, yes, but it doesn't keep the multiplier high enough to really crack the high scores. I think I got to the point where I was killing them TOO quickly to maintain a high multiplier at the end--and that's VERY COOL. Really gets my noggin joggin. Add in some more enemies and you've got an absolute banger on your hands.
Here's the video of my playthrough (still uploading & processing if you see this right away), I hope it helps!