Major issues I've noticed with the WebGL beta, asides from the lag.
1. Death does not trigger properly. when you die, you are able to continue to act/fight until your team respawn timer hits zero, at which point you return to your base as if you had respawned.
2. Health bars do not update properly at all (A few days ago when I tried it, the shield would always show as full, now both health and shields always show as full for both you and other players)
3. Wrong weapon being displayed for opponents happens quite frequently