The Makefile needs a lot of work. In the meantime...
<Command><Space>Terminal<Enter>
If you don't have Homebrew installed already, download the latest release (look for the .pkg file) and install it.
From the terminal prompt, type:
brew install raylib
Run the command:
clang++ -std=c++11 -Wall -I/opt/homebrew/include -L/opt/homebrew/lib \
gameWindow.cpp -lraylib -framework OpenGL -framework OpenAL \
-framework Cocoa -framework IOKit -o SlimeFrenzy
Then, run the compiled binary:
./SlimeFrenzy