HMV are selling "Cookie & Cream" for the Nintendo DS for £7.99 (inc Del.)
You can get cashback through the usual sites (e.g. 5% Quidco, making it just £7.59)
The next best price seems to be £9.99 from dvd.co.uk
'Cookie & Cream' distinguishes itself from other platformers by proving the old adage, that two heads really are better than one. 'Cookie & Cream' is an innovative puzzler, which tasks gamers with controlling both main characters at the same time. On the top screen, Cookie is controlled using the traditional directional pad and buttons, while Cream is controlled on the bottom touch screen via the stylus and microphone.
Players guide Cookie through the game, using Cream to help his partner by removing traps, enemies and a host of other obstacles they encounter in their quest to uncover who has stolen the moon. The secret to beating the game is in mastering both characters and knowing when to use each at the best time!
Colourful heroes Cookie and Cream are now ready to take the Nintendo DS by storm. Featuring additional WiFi connectivity allowing multiplayer battles for up to four players and cooperative two-player gameplay.