I found that threat and it seems not to be resolved. I have the same issue on my game.
My hero is using the platform behavior. When my fps is fine, I can jump over a wall corresponding to the jump high. BUT after testing my game on my laptop, which has a bad fps :
Chrome / Nodewebkit : I can't jump over that same wall. My jump is less high.
Firefox : I can jump over wall I shouldn't. My jump is more high.
The jump should be fps independant but it seems it is not.
So the player can definitly be blocked or pass an obtacle he souldn't if he has a bad fps. This is a HUGE issue.
Any news about that ?