Build instructions for linux are in the readme.md in the git repo. You don't need a makefile, you just call gcc, as there is just a single c file:
gcc source/main.c -lSDL2 -lGLEW -lGL -lm -lpthread
SDL2 and GLEW are required - if you don't have them installed you can do so by running
sudo apt-get install libsdl2-dev
sudo apt-get install libglew-dev