The game is written in the old and almost forgotten Free Pascal with the use of the crt module (which isn't much young and known too).
Gameplay is pretty straightforward, control keys are WSDA & Space, also Esc and Enter. Go to the info menu right in the game to find out more.
The point of the game is to scorch all nine bishops, though it is easy to make it impossible (by default you have no chances). The difficulty can be changed by changing the r and ressurectBi constants in file units/constants.pp.