Turning to the pure arcade game - in fact probably the purest arcade game - we find none other than those old Space Invaders lurking at the top of the green screen.

Is there anybody out there who has never played this? There was a time when every club, pub or public place seemed to have one of these machines. Now if you play one you're likely to be struck by how primitive the simple combination of dodging and shooting is, compared with today's top machines and how addictive that simple formula is.

Invaders was always a favourite for new home computers, if only because it was simple to program.

No doubt this didn't give its programmers too many sleepless nights. All it takes is a horizontally moving missile base, rows of invaders pelting you with boulders or fireballs or whatever invaders pelt earthlings with, and a collision routine.

It's all proficiently done, though it's annoying not being able to fire while moving, but at this price many people's reaction will be, "So what? It may have a horrible fascination, but it doesn't seem to get anywhere pretty fast". And the £13 asking price is an awful lot of 10 pence coins down the slot for a slice of nostalgia.