Working on a homebrew project, as with any personal goal, takes desire, motivation, and willpower. At first, a project is exciting and fun; you are more easily motivated to dedicate time and concentration to keep making progress, to see how good it can get and what you will be able to accomplish. You imagine a fun game and much positive feedback. But eventually motivation and desire to work on a project collectively evaporate like the morning dew. "I am getting tired of working on this.