Dave Gnukem is a 2D scrolling platform game similar to, and inspired by Duke Nukem 1.
The program started life in 1994 and didn't see any significant development between 2004-2016, so it's no surprise that it's a little basic.
How basic? The game help describes the plot as "Shoot anything that moves".
Still, there are plenty of plus points. The package is compact (<7MB). Doesn't need installation. Doesn't have any stupid dependencies. Runs on the most ancient of PCs up to Windows 10 systems.
It's also good fun to play, if you like this kind of thing, and has the supporting features you'd expect (redefine keys, save/ resume game, high scores etc).
2017/06/22 - Version 0.70 [Windows only]
Add new basic 'Instructions' option to in-game menu
Fix: Potential game 'freeze' in teleporter if exiting level editor (or holding in action key)
Added "-scale N" command line option (1 = 320x200, 2=640x400, etc.) (if passed, this overrides the default behavior of attempting to "intelligently" select the scale factor based on e.g. desktop resolution etc.)
Fix: "Key polling behavior is subtly incorrect" (this should slightly improve the character control, especially if trying to move left/right one block only)
Minor sprite and level improvements
Add hero jump/landing sounds (credit for the sounds: Juhani Junkala), key pick-up sound, and more
Increase gameplay viewport width from 12 to 13 blocks