There’s no g++ in mint by default. That’s easy to fix, though.
First try sudo apt-get install g++. Then retry points 3 and 4.
If that doesn’t work, find the actual name of your g++. To do this, open a console, write g++ and then press escape or tab twice so that it tries to autocomplete it. It should autocomplete to something like g+±4.1. Then execute ln -s [that g++ name you just found] g++. For example, ln -s g++-4.1 g++. Then once again retry 3 and 4.
I forgot to mention: when you want to update, go to the directory from point 3, execute git pull and then the make command from 4. No need for the git clone part.
Command from point 4 can take a lot of time (an hour), but if it keeps writing text every few seconds, it is working. You want to always have RELEASE=1 in the line with make or your game will be the debug version and debug version is incredibly slow.
You don’t need to give up tiles, your problem isn’t related to them.