Control buttons not showed on Chrome for Android

Hi, I use a Samsung S4 to try the game and you can see from the screenshot below that the Unicode characters for the left button and the right button are not showed.

The version of the browser is Chrome 38.0.2125.102

They buttons are not showing because there is an error in the code that you need to fix?

[GW3CRT]

I have just tested the game on Samsung and IOS it is Displaying the control button