Me and a friend have resurrected an abandoned project which created a PC port of the Amiga game Mayhem http://www.lemonamiga.com/games/details.php?id=2972.
We have created finished off a lot of the missing elements and added new levels and features.
There are ports for Windows - https://github.com/martinohanlon/mayhem
and Raspberry Pi - https://github.com/martinohanlon/mayhem-pi (which it runs REALLY well on)
Any comments, thoughts and suggestions would be welcome.
I made a blog post which has got some other information and videos on http://www.stuffaboutcode.com/2016/06/mayhem-2-open-source-cave-shooter.html