Dave Gnukem is an open source retro-style 2D scrolling platform shooter, inspired by and similar to Duke Nukem 1 (a famous original 1991 game that launched the Duke Nukem series). It currently runs on Windows, macOS, Linux and various other platforms. It is written in C++ and uses the SDL library. It features an integrated level editor. Note this is not really a 'clone' or a 're-make'; it is probably most akin to a parody.