I'm not a linux user myself but here are some general tips that might guide you on your way:
FPV Freerider is distributed as a Linux executable, not a package. Create a "bin" folder in your home directory, this isn't necessary but traditionally, binary executables go in the bin folder. Unzip the FPVFreerider_linux.zip file into that directory. Open FPVFreerider. Right click on the appropriate executable for your system (32 or 64 bit), and select 'Properties'. Click the 'Permissions' tab. At the bottom of that tab check: 'Execute: Allow executing file as a program'. Now when you want to play, just double click that icon.