For the first issue, did you set the physics mode to framerate-independent? Because by default it is framerate-dependent and can cause such issues.
And the second one, did you check the collision polygons of the tiles? The character just bumps into them it seems. It´s probably better (and more performant) if you use an extra invisible collision object to avoid that since you can just strech them at will.
Thanks for the reply. I did set physics to frame rate-independence and while it did 'break' some of the actions I still observed the same inconsistent difference between the Chrome and Firefox versions. Here's my code, I'm not sure if there's anything glaringly wrong here:
For the second issue, yeah I'm aware the way I'm doing this is not the most performant, it's just much quicker to make levels this way, I can randomize the frame and angle of the tiles at the start of the layout for variation and the geometry and graphics are just there as I build it, but yes perhaps I can't get past this issue without a better process.