Algodoo

Second gun I've made. All thrusters, no thyme.

Right = Ready
Up = Reload
Right Again = Fire

Press reload for at least one second before releasing.
If the empty casing doesn't fall out, let go of reload for as short as possible, then press again.
If the new casing doesn't fall into the firing chamber, just reload again.
After firing, make sure to press right again BEFORE reloading.