It's a shame. For such an awesome manga/film as Akira is, its games have been pretty shoddy. One, however, was so shoddy it was never even released. The story of this missing game is one that's eluded folks for some time, but today, we've finally got some footage of it (well, the Genesis version at least).
And whaddya know, it looks awful.
This footage, of the Genesis version of a game also destined for the SNES, Game Gear and Sega CD, was captured at the 1994 CES, and some of the problems - like an apparent freeze - can be explained by it being early code. Some of them.
Remember, this is a licensed game that THQ cancelled.
Note however that while the Genesis/Mega Drive version was by all accounts trash, the SNES game was almost completely different (much like the Jurassic Park games), and sounded much more promising.
Cancelled Akira game [Unseen64]