Okay. I managed to get the dependencies installed and AM compiled. When I ran sudo make install, it seemed to install, it created a directory, but it isn't showing up in my installed programs.
In case you are curious what went wrong with the dependencies the first couple times, apparently, when I was manually downloading the dependencies before, I accidentally changed a software source server and since it didn't have a Release File, it would refuse to download anything from it. I manually changed the server, and it downloaded the dependencies fine.
Here's the output when I told it to sudo make install:
jarvis@pop-os:~/attract$ sudo make install
[sudo] password for jarvis:
flags: -Wl,--export-dynamic -I/usr/include/freetype2 -I/usr/include/libpng16 -DDATA_PATH=\"/usr/local/share/attract/\" -O2 -DNDEBUG -Iextlibs/audio/include -D__STDC_CONSTANT_MACROS -I/usr/include/uuid -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/x86_64-linux-gnu -I/usr/include/AL -I/usr/include/x86_64-linux-gnu -Iextlibs/squirrel/include -Iextlibs/sqrat/include -Iextlibs/nowide -Iextlibs/nvapi -Iextlibs/rapidjson/include -Iextlibs/gameswf -DUSE_XLIB -DUSE_FONTCONFIG -DUSE_LIBARCHIVE -DUSE_SWRESAMPLE
mkdir -p -p /usr/local/share/attract/
install -D attract /usr/local/bin/attract
mkdir -p /usr/local/share/attract/
cp -r config/* /usr/local/share/attract/