I thought I’d had my fair share of calculator games with Jim’s CASIO MG-777 compilation, but no. Andy Jenkinson has sent me CASIO Digit Invaders, from the CASIO MG-880. No doubt once I’ve worked through to the bottom of my in-tray, I’ll discover somebody’s ported a Victorian game that they used to play on an abacus during elevenses.

Loading the tape without flash loading reveals an interesting fact: the program uses a character array saved to the tape, which makes it probably the fifth program ever to use such a contraption, alongside such classics as Make-a-Chip. The game opens with a slow text scroller (reminiscent of 3D Monster Maze, but without the ASCII-o-vision circus master), detailing the history of the game, along with the instructions and the controls. Of course, being BASIC, it scrolls up the screen like a slug attempting to valiantly make its way through a puddle of honey. Thankfully, the included text file has all you need to know, so you can take a look at that instead of waiting through till next year for the game to tell you.

Basically, the aim of the game is to destroy the incoming numbers by matching your digit on the left with one of the digits hurtling towards you, and then pressing fire to destroy the nearest match. Each wave has sixteen digits to destroy, with each wave getting faster than the last. If the sum of the shot down invaders is a multiple of ten, a mothership will appear which will net you bonus points once taken out. Complete all nine waves and the game will loop, but with the digits starting one position closer to your side. After that, the game will continue to loop, with the starting position alternating each time.

The presentation is generally up to the high standards of an Andy Jenkinson CGC entry. In terms of graphics, there’s not much to look at. The typeface is nicely designed, but being a calculator game, all of the action is squished up in a tiny eight-column display in the top-left corner of the screen. It makes no difference to the gameplay of course, since that’s how it was originally presented, but it’s a strain on my eyes, and that’s saying something considering I’m one of the younger Spectrumites! Sound is sparse but emulates the calculator to an exacting degree, and it doesn’t grate on the ears either, so that’s a plus.

Speaking of Andy Jenkinson standards, this game was later (i.e. half a day later) updated to correct a typo in the opening scroller. That makes a hat trick of updated games.

In the first few stages, the speed is just right – not so fast as to make it tough as nails, but not so slow that it becomes just an exercise in being conscious. Once you’ve worked up to the likes of stage six, however, the slowness of Sinclair BASIC really starts to mess up your chances of progression. The input lag between hitting AIM and having the display update to match is no longer tolerable when digits appear with only a scant second between each other. As a result, what could’ve been a good port, and what was no doubt an enjoyable diversion on its original platform, becomes a frustrating race against time. It’s a shame too, as in all other respects, it’s a very accurate conversion.

All in all, CASIO Digit Invaders is a good example of slow-burn crap – the realisation of its true horrendousness only dawns on you when you’ve already come to like it, and that’s what stings you the most.