Thanks Ashley for the detailed reply.
10fps is an extreme example to illustrate the problem. A more realistic scenario is when framerate drops to about 20 with a complex level on ARM-based Windows 8 devices.
What's strange is that it's not erratic physics behaviour, but more a cap on the maximum velocity. I can never get objects to 'teleport' on a low frame-rate because they can never go fast enough. At 10fps the maximum VelocityX I can get is 1000, even if I apply a million.
Here's a video that should explain better. Each replay is a lower frame-rate (the first is 60, last is 10).
[TUBE]http://youtu.be/dkP24bdIbJs[/TUBE]
"I guess we could add a maximum time step for Physics, to be 1/30. So it's framerate independent down to 30 FPS, then slows down the motion beneath that."
Can I edit the generated source to take a peek at how this affects things?