For anyone running an older version of RetroPie, this game successfully installed on 4.3 for me. Note that I ran the normal install process but then had to manually move the install script module from ext to scriptmodules/ports, and then install like a normal port from within RetroPie to complete. The keymapper is indeed buggy, using it with my Xbox 360 controller corrupts the Dpad mapping for the game. So you basically have a choice between accepting the default mappings or losing Dpad support (with the game still being playable via the joystick). FYI, I tried @Lolonois' script but it errors out because of missing dependencies related to my older 4.3 install.
Regardless, this is a frantic and fun game...definitely worth checking out!