I'll upload the power of 2 sprites and investigate the firefox issue with the map builder tonight.
Great to hear about the framereates on the mobile devices - stick some advertising space on the walls of the game and you've got a monetised adventure that everyone can enjoy with no intrusive pop-ups.
edit - the sprites have been updated along with the map builder, which now supports wall texture re-ordering.
The mouse control version of the raycaster itself is here:
http://fx.barcodebattler.co.uk/waveSphere/webglraycaster2.htmThe only problem I have with the mouse control is that the slightest movement of the mouse, even when it's not over the canvas, causes the camera to rotate. Still, it's proof that it works and between the 3 of us we can figure out how to make it better.
The new starting position has greatly improved the framerate at the beginning of the game. I can't offer an explanation as to why the old one was causing an issue, but sometimes things happen in programming that nobody can adequately explain

I'm wondering if a semi-transparent D-Pad displayed over the lower-left corner would be better than mouse control.
Pressing one of the virtual buttons would then cause the camera to move forwards, backwards or rotate accordingly.