One of my favourite activities is trawling charity shops for useless bits of old tech at bargain basement prices. I can’t resist things that are endearingly crap and hopelessly outdated! One of my recent purchases, however, turned out to be surprisingly good, especially as it only cost me a quid.

I present to you the “eSudoku 15K”!

This was in a box still with most of its shrink wrap in place, so it had clearly never been used. It’s a classic example of a single-purpose electronic device – in this case, it’ll play you fifteen thousand games of Sudoku, which I’m sure will keep even avid players going for a while.

I know a few (mainly older) people that are Sudoku obsessives, but until I got hold of this thing, I’d never played it. I knew the rules, but had never attempted to get my head around it. This little device soon taught me how to play, and proved surprisingly addictive once I’d got the hang of it.

Using it is all pretty self-explanatory, really. It plays Sudoku, and that’s it! On powerup, you get to choose one of three skill levels. This dictates how many squares already have numbers in them at the start of play. On top of that, you can pick “Easy” or “Pro” mode for each level. The former will immediately reject wrong inputs for the empty squares, and was useful for me in learning how to play, but it’s not really Sudoku if it’s that easy! “Pro” mode doesn’t give you any feedback until the end of the game, when your inputs are either declared correct, or you have to go back and try and find your mistakes.

The screen is crisp and clear and easy to play on. Each cell of the board contains a classic seven-segment calculator digit. The controls consist of arrow keys and the nine numbers you need to input. On top of that, you can get hints, but I’m not sure they do me much good! By default, sound effects are on, and they’re very loud! Each press of an arrow key results in a loud click, and if you land on one of the pre-populated squares, you get loud beeps until you move, and you’re prevented from input on those squares. The sound effects are very irritating (especially for those around you!) but thankfully there’s a mute key. It’s the most important one of the lot, in my opinion…

Gameplay is pretty much as you’d expect, although it’s slightly different from the paper experience – you can’t make notes as you go, for a start. Once all the cells are full, the game will play you a little fanfare if you got everything right. If you’ve got things wrong, it’ll do nothing, and leave you to try and track down your errors.

The challenge is to complete the puzzles as quickly as possible. Play is timed, and on the level selection screen, you can see the quickest time for solving puzzles at that level.

That’s really about it – it very much does what it says on the tin, and it works very well. The only real criticism I have is the sound effects – besides that, it’s fun to play and easy to get hooked on. It came with a little leather sleeve to keep it in. The device itself is white plastic and feels a little cheap, but it seems to be easy to keep it clean and in good condition. The instructions were quite helpful, both in describing the game, and how the product is operated.

Rather oddly it needs two types of battery – AAA batteries to power the game itself, and a button cell to maintain the memory while the AAA batteries are replaced. The only thing the memory does is maintain the quickest time data, but it’s quite nice that you won’t lose your best time, especially if you happen to be proud of it.

As far as I can tell, this product dates from around 2005, back in the days when there were quite a few games like this around. The thing that made them all vanish, of course, was the smartphone – suddenly apps to play all sorts of games were available, and you didn’t need to carry separate devices. As you’ll know, however, I’ve tended to view my smartphone as the root of all evil these days, so when I’m off on a long journey, or just want something to do when I’m relaxing, I’ll happily reach for this thing. It really has proven to be a lot of fun for next to no money.

Have you got hold of any vintage single-use devices like this? Do share if you have!