This is a faithful recreation of Countdown, no more and no less.
Presentation is sparse - no graphics of the presenter or contestants for example, it's just literally the letters board and the Countdown clock. But the little presentation that you get is nicely done in the recognisable Countdown style, and most importantly you get the famous clock music.
The format is exactly that of the show, with 11 letters rounds, 3 numbers and a conundrum at the end. There are 5 difficulty levels, so you can have a good competitive game no matter how good at the show you are.
The computer tells you the longest words that can be made at the end of each letters round, as well as offering the ideal solution to each numbers round, which is a nice touch. Unfortunately, a major problem is that the computer has no conception of which words are in common usage and which aren't. So on beginner level the computer opponent will play obscure 2-letter words such as 'ac' and 'oo', rather than more obvious words like 'cap' or 'car'. This wouldn't be so bad if the computer gave you a definition of these bizarre words, so you could at least find out what they mean, but it doesn't. This is a pretty poor omission. After all, Scrabble 2009 on the DS does it, so why can't Countdown? Unfortunately, the conundrum round also tends to use such what-on-earth-does-THAT-mean words (unlike the TV show, where the conundrum words are usually relatively familiar), so a lot of the time you won't stand a chance on the conundrum (although miraculously the same computer opponents who can't pick out simple words a 3-year old would know usually manage to solve the conundrum in the last few seconds).
The other main problem is that the way of inputting your answer in the numbers round is quite fiddly, which means you can end up running out of time even when you know the answer. As another reviewer pointed out, there's no option to use brackets, so for example you can't write 50 x (9 - 1), instead you have to write 9 - 1, and then write 50 x the 8 that the previous sum has produced. It may not sound like a big deal, but in effect it means you only have 20 seconds to work out your answer instead of 30, because you have to set aside 10 seconds just for inputting. It would have been better if you could declare your answer at the end of the 30 seconds and THEN input it, like in the show.
Despite these problems, the game does play a fun game of Countdown which fans of the show will enjoy. Its no-frills no-extras nature means it's not worth the RRP, but it's definitely worth a tenner if you like the TV show. Let's hope next time the game's designers include a dictionary which gives definitions of words, which would push Countdown DS up to being a 4-star game.