If you want to compile it yourself, you can:
- Build it with Visual studio - if you have visual studio with visual c++ installed, open the solution and build it. There should be the executable in (Soulution folder)/lightmage/build.
- With g++ (MinGW or Linux) - GLFW (one of used libraries) uses binaries (.lib / .a), and in the source zip there is only windows version - .lib; so you need to download (and build if you don't download precompiled binaries) and add the .lib/.a files into /lightmage/libraries/libs/. Then (Solution folder)/lightmage> g++ -std=c++17 -I./libraries/include/ -L./libraries/libs -lglfw3 -o ./build/lightmage ./src/dungeon.cpp ./src/enemy.cpp ./src/glad.c ./src/main.cpp ./src/spell.cpp ./src/stbimpl.cpp should work; on Linux add -lGL -lX11 -lpthread -lXrandr -lXi -ldl. Also chmod +x will be propably needed on Linux.
Also, what hardware and OS do you have? Might take a look what causes the issue here :).
Another way to try it would be to try another machine :).