We might as well try it out, though I’m not so sure the emulator will play nice with it.

Duke Nukem: D-Day (also known as Man of Valor) was supposed to be the blonde macho’s first PS2 adventure. It was developed by the now-defunct studio n-Space, the team responsible for two PS1 episodes. Despite rumors that the game was nearing completion, it was canceled and never released. However, a 2001 prototype with twelve playable levels has surfaced on the Internet Archive!

The uploader claims that it is about 90% complete. It’s quite playable, but still noticeably unfinished. There are no scenes or voice-overs, but it seems to contain all the key action elements, albeit in a somewhat sketchy form. Duke starts in a strip club (he wouldn’t be Duke without it), then travels back in time to fight the Third Reich and their alien allies off the coast of Normandy. The game culminates in the storming of an alien mothership in Antarctica. It’s not as imaginative as Duke Nukem: Time to Kill, in which Duke jumped all over space and time.

The controls are reminiscent of the pre-PS1 era. The left analog stick is used to turn and run; the shoulder buttons are used to move sideways; and the face buttons allow you to shoot, jump, and perform a Max Payne–like side jump to prevent Duke from sustaining significant damage. There are few weapons to pick up in this prototype, but Duke’s golden Desert Eagle with unlimited ammo (wasn’t he inspired by Lara Croft?) is a solid choice because it fires as fast as you press the button.

To try out the prototype, you’ll need either a PS2 that can play unofficial software, such as a FreeMCBoot memory card, or a PS2 emulator, like PCSX2. Since this is an early prototype, n-Space has included a lot of debug features, allowing you to jump to any level. The uploader also mentions that the game was in development until 2003, so perhaps an even better version will emerge.

Source: PCGamer, Archive.org