Ok, Some technical implementation details for those who are interested!
I won't post code as it won't be very helpful without context, but if you have a particular problem with a specific piece of functionality I'll see what I can do.
As mentioned all the physics is with chipmunk.
The fuse is implemented with shapeless bodies attached with pivot joints and then drawing lines between the bodies' centres. To smooth out the line I use a "catmull-rom" algorithm to subdivide the line segments into 4 smaller smoother segments each before drawing (using openGL DRAW_LINES).
The fuse simulation is the main bottleneck in the game. Balancing appearance and framerate was tough, and the smoothing algorithm saved the day as it runs much faster than adding 4x the number of links.
The links are removed one by one from the fuse as it burns, but we move the spark sprite smoothly to make it appear nicer.
The thrusters are chipmunk bodies which have the fuse attached and which get a continuous force applied when they burn down. They are attached to the rocket with 2 pivot joints so they won't swivel around. When they're finished burning (based on elapsed time) we detach them and remove the force and flame sprite which gives a nice effect. We then have a timer to go and clean up these spent thrusters as they will slow the physics down otherwise. It will try to remove them when they're off-screen which is a worthwhile touch.
The rocket's shape is simply modelled with 2 separate concave shapes (for the left and right) to give it a bit of a nicer feel than just a triangle.
There's not much else to it. I'm glad the game is interesting and thanks heaps SmallMike for pointing out the fact that we're in the Hot New Games section! We're pretty excited about that now! :)
