Algodoo

Ridiculously powerful and very accurate mobile gun. Very much like my last gun (http://www.phunbox.net/details/9043/) but designed for power rather than versatility.
A and D to aim, W to shoot. Arrow keys to move. If you shoot too rapidly the swining arm will glitch all to hell.
The odd body design is to better withstand the ridiculous kickback. The kick (and subsequently the ridiculous power) is caused by the small superelastic yellow ball on the swinging arm. I hadn`t seen this feature used on a mobile and aimable gun, so here it is.
The tower target is neat enough in its own right. Reduce the density to something really low for a funny effect on impact.