Target Renegade
This game from Imagine is the spiritual successor to the arcade hit Renegade (though I don't believe it was ever a coin op itself). It takes the fighting game into the gritty reality of a downtown district and has you fighting in such glamorous locations as a multi-storey car park and a pool hall. Along the way you are able to pick up playfull little weapons like a lump hammer and a pool cue. Pleasant!
All 3 versions are quite different and quite similar at the same time.
Amstrad

What imediately hits you is the lack of a title screen. You get a simple grey screen with a list of options.
When the game starts you get an OK theme tune that is played in nice soft notes. It does tend to grate after a while though. The punching sounds are very basic, but at least functional.
The graphics for the CPC version are by far the worst of the 3 (its a pity that the small screen doesn't show how truly awful they are) and automatically remove the right for any Amstrad owner to call the C64 blocky. This looks like it is made from Lego and really does detract from the overall feel. The levels do not scroll which can be quite disorienting when the screen flips.
The gameplay however is pretty good and worth persevering with.
Commodore

The same dull title screen and the same music are presented to you, but I do think that the harsh tones of the SID chip detract from this tune.
The graphics are very different to the CPC version and are nicely drawn with the bikers riding impressive drop handled motor bike. There is a great touch with the eyes below the play area that feel every blow that you take. The levels scroll nicely so avoid the flip effect of the CPC.
This game is great to look at, but you should really stop there.
The gameplay is missing completely and it feels like you cannot land a kick or punch. The ingame sound effects have gone missing, which loses the satisfaction of a thwack when you finally do manage to lay a hand on the bad guys. Overall this is a look but don't touch affair.
Spectrum

I don't want to get a reputation for biased comparisons (read some of my others and you will see the C64 easilly beating the Speccy a couple of times), but this version is just better at everything.
The same dull title screen is there, but this time it is a black screen with some colourful lettering, making it look a bit more inviting.
The ingame music is the same as the other 2, but closer to the amstrads smoothness and the sound effects do the job well.
The graphics though are fantastic and depict the hero not as a long haired rambo wannabe (C64) or something picasso threw up (CPC), but as a 50's styled rocker, with an elvis haircut and turned up jeans. He is bigger than the other versions and the inner city locations really suite the monochrome presentation. The overall feel of the speccy is very British as opposed to the C64's American feel and the Amstrads Legoland.
The gameplay is also spot on for the Speccy, with smooth scrolling and fair fights you really want to continue.
Overall
1st - Spectrum - Great looking and great to play. A gem.
2ns Amstrad - Shitty looking, but good to play.
3rd - Commodore - Great Looking, but shitty's ugly sister to play.
Now what ever happened to the remake some forum guy was making a while back?