In many of my creations I have needed the ability to detonate something. So heres a suggestion, an element called BOMB, it will sit whereever you place it like ice goo or metal and will be a brown colour slightly darker than goo. It will react with any form of fire or magma. Basically when you press a button for instance lets say that button was D for detonate, all bombs on the map will explode.
This would be quite a useful feature, and for simon relatively easy to write.
I think if this were to be implemented. It will be a very very long time. There are much more effective things to be added to the powder toy which will be enjoyed more.....like my plasma :D lol