Wall-bomb

I thought it could be a good idea have few trap-walls that explode when destroyed. It could be a clever upgrade. The damage should be medium, enough to kill lower troups or other wallbreaker that want to proceed toward the next raw of wall. Just few of these could make the game more exciting. For example players may put them spread in the village or they may put them in raw ot together and let them detonate in the same time (this may be a feature of those wall-bombs, chain explosion if they are linked.) Obviously the number of those walls should be restricted. The upgrade may allow to increase the strength and the size of the explosion (like a normal bomb) and also lowering wall life in order to have a faster explosion, thins may push some player to use earthquake spell to destroy walls without risks.
Thanks for the attention.
PS: sorry for my English or errors.

You can pretty much do that already, just follow this guide by akiyume: http://akiyume.weebly.com/th9-single-bomb-usage.html