HTML5 and WebGL both work perfectly fine in Opera. There is no excuse for blocking it. If a browser doesn't use those programs, the game simply won't play. With Opera, this isn't the case - html5test rates my browser's capability as 519/555 and getwebgl verifies webgl support. I can play any and all other html5 and webgl games just fine.
Your decision to block a browser just because it isn't one of the main three is unfounded and unfair. Since you refuse to let my browser determine the playability of the game itself, I refuse to give your game a proper rating until you fix this.