Needs a little bit more.
This game is a very innovative spin on a fairly old genre. I liked the idea.
It gets incredibly tedious and frustrating to play however. It really needs to have walls that prevent the portals from exiting an area rather than destroying them entirely and a reset button that doesn't totally wipe the map. If you had something that left the rings in place but reset the box the game would go much smoother, as usually missing the shot comes down to a minor issue in placement/alignment.