Cytadela is a conversion of an old Amiga first person shooter. The original was created in mid 1990's by Virtual Design, and released firstly in Poland and then in other countries.
This is a single player game in which a player fights against AI enemies. The goal of the game is to find six bomb parts with which the Citadel has to be blown up. To achieve it, the player not only has to defend himsefl against the enemies, but (s)he also has to solve many riddles, such as swithcing apropriate buttons in order to open some door etc.