Worms engine is very simple by comparison. No rotation and the physics is certainly not very accurate, as solid as it feels when playing. Again, interactions between objects are the exception rather than the rule; interactions happen "at an instant", mostly objects are flying through free space, which is relatively trivial. Objects do not balance on top of each other. The terrain is essentially static. On Angry Birds the scenery is almost entirely composed out of moving objects in constant interactions with each other. This is a completely different kettle of fish. Do-able on a small scale, I suspect. I wouldn't try to write a clone of Angry Birds but a "physics game" along similar lines could work.
But the resolution of the graphics need not have any impact on the game play. I really do not understand this objection. Objects can be moved behind the scenes at any resolution, and I don't see anything in Angry Birds that relies in especially fine details, on the order of an Amiga's low-res pixel.