10 regular levels, and 5 boss levels.
I just started now doing the bonus stages, there will be 8 bonus stages, 4 ninja type (like in this picture), and 4 first person type (artist still drawing it).
Above is the ninja type bonus stage, in the first level of each mission there is a pickup for this bonus stage.
In this level, ninjas will come out of windows, and Dan will need to kill them before they escape from view.
I am still implementing it.
The 3d style bonus stage will play after each boss fight (apart the last boss).
PS: If you remember or saw the original Shadow Gangs video, there was a section of the demo where the ninja's come out of windows, I wanted to put this action scene in the game but didn't find a place for it.
So I put it in this bonus stage!