Algodoo

It resists rotation exponentially more depending on how fast you try to spin it. It can turn slowly with little resistance, but hit it and it won't turn at all. Change spring strength, density of the red bars, or spring target length to change the strength, although even at its current setting it can be shaky and likes to turn sometimes, and occasionally explodes. Could probably be improved, but I'm too sleepy to figure out how.

And don't let the resemblance to a Raunit get your hopes up; that was just out of habit, although when I tried to make a triangle version it exploded. It does not seek out any angle in particular, just resists rotation. Phun is running out of glitches!