Oh man, this is one of the most viscerally satisfying action games I've played in a long time. It's a $10 physics game out of russia in which you pilot a whirlybird helicopter gizmo with a large weapon attached. Using the mouse you move the whirlybird and the weapon freely rotates with plausible physics. Aim your blows well with the right amount of force and enjoy the satisfaction of seeing your enemies slammed into the destructible scenery.
The game has a huge assortment of weapons with different levels of length, weight, and sharpness, and thanks to the physics engine they're all unique. Even your starting rock on a chain controls way differently than the iron ball on a chain. Then if that's not enough, you can attach a pair of weapons end-to-end. For example, in one monster-slaying level I sported a heavy sword connected to a light dagger and turned myself into a flying buzzsaw. Fun fun fun!
There is a big misconception that this game is unfairly difficult. Indeed for the first week I was in a keyboard-flipping rage as I fought the seemingly unfair tutorial levels lightly jarring the badguy with my polo mallet over and over again while he destroys me in one strike with his steel spiked hammer. So here's a SUPER HUGE IMPORTANT PROTIP: Don't trust the game's approximate mouse setup in the options menu (to the left). Set Mouse DPI to 100. NOW your weapon will strike with the force intended, and those unfair early missions turn into hugely satisfying slaughters.
Note that if you hate steam, you can also get the DRM-free installer off Gamersgate. This game is justification alone for the purchase of a trackball.