Dave Gnukem is a cross-platform, open-source 2D scrolling platform shooter inspired by Duke Nukem 1.

Duke Nukem 1 was a famous original 16-color 320x200 'classic' game released by Apogee Software in 1991 that launched the Duke Nukem series.

Default Keys:

Left/Right: Move left/right
Ctrl: Jump
Alt: Shoot
Up Arrow: Action key (for e.g. opening doors, using teleporters or lifts, activating the exit, etc.)
Escape: In-game menu

PgUp/PgDn: Increase/decrease volume
Insert: Toggle sounds on/off

To open doors, find the correct color key, and press the action key on the 'lock' nearby the door(s).
Power boots allow you to jump higher.

No installation is required. Simply extract the files and run DaveGnukem.exe.