You can easily earn money by taking risky photos. When you you encounter a big monster in the hilly, it will be a fish-like sea monster. After the intermission sequence, take its picture and send it to the research center. You will get 2,000 credits for it. When you enter the factory, you will encounter another monster. Take its picture and send it to the research center for 2,500 credits. Take all the pictures of fish, animals, rats, and friends and all the people that roam in the street and bars and send them to the research center.
After getting the camera and photographing the beetle, take a picture of the kids, the dog, and Pey'j to get some pictures for the scientific society, and some money. Likewise, go to Mammago's and take a picture of one of the attendants. Also, in the Pedestrian District, take some pictures of the people there. Some might be an "unidentified species".
In the battle with the Domz priest, he will eventually tell you that you are out of control with your soul, and the directional controls will be reversed. A practical way to overcome this is to simply flip the keyboard upside-down.