Reaction is a game to test your focus, split your attention, and sharpen your reactions. You have to keep your combo up, but break it before any of the targets sneak through. I find it a bit of a challenge, and it frustrates me too!
Give it a go, and try out Reaction! (google play link)
If you have any comments, please feel free to shoot me an IM here, leave a reply, or send me an email via the in-game link.
Hope you like it,
edit: If you prefer the full link: https://play.google....igames.reaction