ONE of life's more cuddly ironies has to be the arcade conversion. We spend many hours and pounds for the thrill of seeing our initials on the screen in a (possibly) rather dodgy establishment. After a while we dig out some more cash to spend on the home computer conversion, which we batter away at for a few days.

All we get to keep is our initials on the screen and a very short-lived hit of adrenalin. The other parties involved get our money in large quantities. Who gets the better deal? He asks in a concerned Channel 4 consumer programme kind of way. Because conversions cost publishing houses a lot of money, would it not be cheaper to nick some good points from popular games and add a completely flimsy to the point of being see-through plot? Would Robert not indeed be your parent's sibling? Ah, but games like that are easily found - in the bargain bin, at the back of the software drawer, in a skip...

Without polish or class, or at least some good honest hype, more money is lost than saved.

Currently, Digital Magic Software - or DMS to those who want to sound in with them - are doing with arcade games what Frankenstein did with dead bits, although with a slight difference. Frank took the best bits but kind of spoiled them all when joining them together. DMS takes good ideas, stitches them together with good coding and the joints are nowhere to be seen.

DMS, to use another tedious analogy, are the Classic Car restorers of the computer entertainment world. Trained Assassin has got more arcade elements to it than a fan heater on Brighton Pier. On the lowest level it is a scrolling shoot-em-up with add-on weapons; no chocolate watches awarded for originality. It has got five levels. "Zz zz zz", comes the reply. It has got a tiny plot, all about destroying King Rhizoflagellates and creatures "whose touches are fatal". With one mighty, apathetic accord, humanity manages a defeating "  !". Not very impressing sounding, isn't it?

There is a fair amount of money in the trained assassin business; there is equally as much in the untrained assassin business, but it goes to the next of kin. There would certainly need to be big cash involved to face King Rhizoflagellates's horges of nasty things, all of them with more kick than an uprated onion bhaji.

The standard weapon deals quite adequately with the first few waves, but things very soon get out of hand. You will need the laser and the orbiting-buddy weapon to even think of getting rid of them.

Each stage can be learnt; in fact it is vital to do so because some bits are dead ends and you get crushed by the relentlessly scrolling scenery. There is not as much scenery as you would expect in an arcade machine, but there is certainly enough to get in the way.

The first level has slightly futuristic bits all over the place, like a simplified R-Type 1. It is fairly predictable once you learn where to go and what not to do and ends with a fairly traditional Big Nasty Dragon. It serves as a good warm up for the rest of the game and has enough initial wow-value to keep any gonzo arcadist happy.

The second level scrolls down the way, which causes some problems because your main weapon shoots horizontally. It has bubbly scenery, not dissimilar to Starquake, the old 8-bit Bubble Bus classic. It is extraordinarily difficult, far more so than the third level, and could spoil the game if you cannot suss what to do.

Level Three has a desert-cum-ancient Egyptian feel to it, but has the added twist of seemingly solid scenery, which can only be got past once shot. It is a good level, loads of traps for the unwary and just as many for the fully clued-up. It scrolls horizontally but, unusually, from left to right.

Level Four is not for the weak of stomach, nor those who have eaten within the previous hour. It has got flying eyeballs, leaping protozoa, and tracking tumours. This has got to be one of the most tasteless levels of a computer game I have ever seen, but is a difficult blast because the scenery move upwards. Me, I nearly lost my lunch.

The final level is everything a final level should be; excruciatingly difficult, but with features learnt from previous levels. It is uncomfortably similar to R-Type 1 and more difficult than all the other levels put together. When you cop it - notice the "when", not "if" - you get put back to the very start of the level; a pest, but you should have learnt what you did wrong and will be able to avoid it next time.

The team of Burt on coding, Derrett and Law on graphics, and Harris on sound has made Trained Assassin a very fine game. Better, even, than the the last DMS offering, Scorpion. Everything moves quickly and smoothly without fuss or flicker.

The presentation is much better than in Scorpion, with a very nice Tim White illustration on the box, poster and title screen. The effects, although loud and atmospheric, are not much more than OK. The same cannot be said for the title tune, which even manages to sound good through headphones.

I appreciate that rather once-dimensional scrolling shoot-em-ups may not be everyone's pot of Darjeeling, but Trained Assassin appeals to me. It does not say anything new, but it is of a standard that could probably survive unaltered in a real arcade. As good as the Amiga is, few games could manage that.