Graphically the game looks great, this is the kind of stuff that Web 3D needs, given the difference on OpenGL ES offerings on native mobile games and what most stuff looks like.
However I gave up playing on mobile, the system randomly mixes fingers movement between moving the character and zooming, thus breaking any gaming experience, I guess it was mainly tested on desktop.
I think you have mistaken the camera zooming to avoid clipping with the environment with your fingers controlling the zoom. Unless there is some secret zoom gesture I'm missing.
The game is the one mistaking it, all happens with single finger movement.
One second it is going forward, sundenly the next second zooms in.
Well perhaps you are experiencing a bug since mine only does that when there is an obstacle in the way of the camera.