Working in Visual Studio 2019.
If you get an error about glut32.dll missing, copy it from RebelDefence_WIN\glut-3.7.6-bin into c:\Windows\SysWOW64.
The following should work if you have make and g++ installed:
git clone https://github.com/jeffwmair/rebel_defence.git
cd rebel_defence/src
make
./rebeldefence
Gameplay is straight-forward. Use the mouse to point the cannon, click (or spacebar) to fire. Kill the AT-ST's before they can walk past you (the cannon). Shoot down the tie fighters too. Though they don't actually shoot at you.