DaveSpicer says

"Here we have the only dual format game I wrote where a substantial amount of effort was put into making the CPC version as good as possible. If I remember rightly, this was because Codemasters paid a reasonable amount of extra money, rather than just assuming the Amstrad version came "for free" when coding for the Spectrum. It's still not a bad budget title, albeit with some odd behaviour from the AI. There's a good reason for this: the AI was designed to work with an enclosed, Pacman-style maze, rather than the open spaces we actually ended up with. Rather than rethink it, I just tweaked what was there and the results were rather hit and miss. Codemasters wanted the enemies to shoot at you, despite Seymour being unable to defend himself unless shot at from the front. Having seen how badly this messed up the C64 version, I made up a lie about running out of time for the sprites and managed to keep the "feature" out of the Speccy and Amstrad games."