This is an update to Blend #81293.

1. Fixed issues that prevented it working in Blender 2.76

2. Tweaked some textures.

3. Fixed a bug that made it impossible to finish the game.

Demo:
https://youtu.be/HDcpnJUW_Hg

This game demonstrates a way to use shards from the cell fracture tool without exploding them all at once. In this game a shard is only activated from a direct collision with the projectile or if the shard that is supporting it is displaced. This results in a reasonably convincing demolition of the castle tower by repeated blows from the trebuchet.
Uses only the physics engine plus a script to control shard activation.
I modelled the trebuchet on a toy I purchased from Skipton Castle gift shop.

Thanks to mherpin on blend swap for his [ground texture](blendswap.com/blends/view/81252)

Smoke
Andreas EsauĪs Easy Emit Add-on

Sounds from freesound.org
ryansnook, Small explosion
juskiddink, Distant explosion

Sky Dome:
http://www.tutorialsforblender3d.com/Textures/Textures_index.html