XD opens with a cutscene worthy of a much bigger screen. A cruise liner is set upon by a legendary Pokemon and a gang of helicopters from the extra dimension (which is what the XD stands for). The Pokemon, a Shadow Lugia codenamed XD001, drags the liner out from the waters and makes away with it through the night sky. It's a dramatic, well-executed set-piece which immediately establishes the blockbuster style of the game - Pokemon XD is the real deal.

At first you can't access any areas apart from Ash's home and Professor Krane's lab. But after interacting with the characters and searching through the house for your little sister Jovi, your mother sends you on your first mission. Moving around the world is not as engrossing as it could be - there's no Final Fantasy-style wandering involved and no treks. Instead, a single click on a location initiates a cutscene which shows Ash riding down a dirt track on his scooter.

The design of each location is such that you can choose to either follow sequences that progress the story, or take time out to investigate less central places and meet unimportant, but not uninteresting, characters. The advantage of following the second route is that more level-up opportunities arise, extra side-quests appear and new items can be found and bought. You're rewarded for not rushing through the game and as a result, you can easily get a good 20+ hours of engaging play from the main adventure.

Other Pokemon be obtained when a scientist comes up with a revised version of the Snag Machine, which enables you to snag other trainers' monsters during battles to be organized by your PDA. There are 83 Shadow Pokemon scattered throughout the game, all of which can be caught in this way. You can hold up to six Pokemon in your line-up, and you can make substitutions in battle. It's a versatile system that really gives it the spirit of a traditional team-based RPG.