Game is working good for other players, its definitely playable(read communication of other players above) , if its not working well for you, you should get a better computer.Though agreed, it doesn't have performance like Webplayer version.
As we said before, we rely on browser's WebGL update(SIMD coming next), plus we are working on improving it with every update, and have some other plans for the game yet.
No doubt, game has delayed server responses, for which we have to find some kind of workaround for WebGL. This is something that needs research.
Moreover game is having 40k daily active players(ping me directly if you want to see those stats ) , with guests being converted to idnet players at a good rate and "retention", which stands a good base.
For other players, who compares FFT WebGL performance with WebPlayer , we have better plans, we'll let everyone know here when we achieve something on that subject.