Akira was not only a globally popular animated film but one that has been immeasurably influential within the industry and outside of it. And as it turns out, there were plans to develop an ambitious game based on said IP back in 1993 for the Sega Mega Drive system. Unfortunately those plans fizzled up, but just recently brand new footage for the title emerged, showing off various incomplete levels:

The hour long video was released by Youtube account Hidden Palace and according to the official description from the video Akira the game was developed by Black Pearl Software sometime in late 1993 for a planned released in 1995. It attempted to do a faithful adaptation of the original film by presenting various key scenes from the film in unique ways.

The game features several genres such as first person shooting, racing, platforming, and beat-em up segments to help illustrate the various points in the movie's story. Thought to have been lost since its initial debut in various media as well as the Summer Consumer Electronic Show (SCES 94) in 1994, an early prototype has emerged and is presented for the first time in full.

Watching the video, you can see the attention to detail in each level and there's some impressive animation in both the cutscenes and the gameplay itself. However, a few sections such as the hospital level looks a bit tedious and difficult to navigate. It would have been interesting to see what the polished final product would have looked and played like.

You can learn more about Akira the game here but some interesting facts include: none of the levels can be completed, the game freezes when it loads the fifth stage, this new footage is from an earlier build than the one shown during SCES 94, several music cues are present in the sound test but are unused by the game itself, you can go back to the level select at any time by pressing start, the first levels do not have enemies, and the game is prone to crashing around the second level.

Other lost games include PS3 exclusive Agent from Take-Two Interactive, Two Tribes' puzzle game Swap This! that eventually released for Nintendo Switch in 2018, and DICE's unreleased title Hardcore which finally saw the light of day after 25 years.