The Fortress of Dr. Radiaki

This is one of the tons of Doom clones that were released in 1994/1995. The story: Dr. Radiaki has created an army of genetically modified creatures, and wants to conquer the world. You have to go to his fortress and stop him. The main points that set it apart from other games in this category: it's intended to be rather humorous, you start with a baseball bat instead of a knife, and you actually have to reload guns (ie you have to hit Space almost constantly).