It started from a lot of Idea sketches, I sketched desk toy, large scale toy, small scale toy, educational toy and so on.
Then I found a castle theme toy which is shooting small mercenary that hide inside the building. So I mainly focused on how to launch a object by using tension of rubber. Mechanism of mousetrap was really helpful to figure out the toy mechanism.
Then I focused on trigger system, which will contribute on user interaction. So in this pace, the idea was knocking down a character while the ground is moving forward by rubber band.