PopCap has built itself a reputation for accessible, infuriating yet ultimately quite brilliant puzzle games. Mystery PI is perhaps one of the firm's lesser known titles, but thanks to a new publishing deal with Focus Multimedia, the game is available for £9.99 on shop shelves across the land.

And it's worth picking up, too, if only because you'll doubt that your eyes are capable of doing their job come the end of it. The plot is simple: you take the role of a private investigator, called in by Grandma Rose who has lost her lottery ticket. Thus, against the clock, you need to help her find her ticket.

You do this by visiting the locations that Grandma Rose has been to, and by hunting down an assortment of other missing objects, before the clock ticks down. And so the mechanic of the game presents itself: each location is a single screen and you need to click on an item once you've found it. Sounds simple, right?

After ten minutes you'll be booking an appointment at Dolland & Aitchison. It's all very well staring at a monitor and looking for an open book that may be sat on a chair at the forefront of the screen, but you'll find yourself examining every pixel to try to find it. More often than not it'll take you a good while to spot it, along with the other things you're required to find and click on.

You can have a hint to help you, but once you use one, it takes a while before the option to use another is made available, and point penalties start to kick in, too. You also get penalised for clicking around the screen with abandon, so you really have to use your powers of observation to break through. Do that, and you come up eventually against a further puzzle to get a clue to the lottery ticket's whereabouts.

This then continues until you get to the end of the game, which'll take you around seven or eight hours. And you'll come out the other side with mixed feelings. On the one hand, its simple concept is backed up by some ingenious design. Some of the disguising of objects is fiendishly clever and to be applauded. That said, the American item names don't help, as sometimes you'll simply have no idea what you should be looking for. Also, we found that clicking on an item wasn't always acknowledged by the game.

But still, there's a delightful simplicity to Mystery PI that's hard not to warm to. It perhaps isn't what you'd expect for a tenner, but it very much continues PopCap's ethos of accessible games that everyone can enjoy. It's worth a look.

At times quite brilliantly put together, but ultimately a simple little puzzle game and not a lot more than that. And watch out for eye-strain.