Recently someone has reverse engineered Duke Nukem 2 back to its original source code [1]

[1] https://github.com/lethal-guitar/Duke2Reconstructed

The screenshots reminded me of Secret Agent (sometimes rebranded as Agent Sam or Secret Agent Man), and indeed Jim Norwood worked on it, too. [1]

[1] https://en.wikipedia.org/wiki/Secret_Agent_(video_game)

Duke Nukem the side scroller was my first computer game and I loved it.

I spent hours playing Duke Nukem when I was a kid. Based on my son's love for absolutely idiotic games, and the assumption that I was like him at his age, that may or may not say anything for its quality, but I have fond memories of it.

Could never get over seeing a bunch of stolen graphics from the Amiga game Turrican 2 in one of them.

Didn't help that that game was far superior to Duke

I loved those first two games. They were hard to complete and a ton of fun.