Yes, it is possible to make a platforming game engine just using physics. See here: viewtopic.php?f=4&t=2961
It takes some work, though. And there are a lot of little things you need to do to tweak it just right.
What sort of interactions do you need? Perhaps you can fake it with another means. If it's just something like you need the player to thrown a physics-y ball, then that's easy. But if you need lots of movable stuff that pushes the player around then yeah, you'll probably need to ditch Platform and use Physics. Just keep plugging away at it.
And if you're having trouble with one particular bit, go ahead and post your .cap so someone can take a look. Vague descriptions like "I've tried this by adding force, but it freezes" don't help much.