Thanks for encouragmeents ! The mouse focus problem is very strange I don't understand if I missed an option before exporting my game. I test the game on differents browsers and I never lost my mouse focus. In the game code I use this line "Input.set_mouse_mode(Input.MOUSE_MODE_CAPTURED)" that normaly hide the windows cursor and focus the mouse control. I presume the HTML export is not fully comptatible with this feature, I mean for some users.