This is a horizontally smooth-scrolling shoot-'em-up for the unexpanded Commodore VIC-20, heavily inspired by the classic arcade game "Gradius" and the VIC-20 community at http://sleepingelephant.com/denial/.
Copyleft (c) 2014-2015 Sven Michael Klose pixel@hugbox.org All rights reversed. It's all yours, too.
You'll need at least exomizer, git, mplayer, sbcl and sox installed. Then download and start 'download-and-build.sh' to clone and build all required Github repositories.
If you get into problems please don't hestitate to ask pixel@hugbox.org about solutions as he's regularly missing out things.