There's no good answer to how you should go about updating a classic, but Bubble Bobble Revolution does a surprisingly good job of demonstrating what's wrong with so many modern games and what was so good about the best of the old ones.
New Age mode is Bubble Bobble's 'revolution', an elaboration of the classic platformer which expands it in almost every aspect. The iconic dinosaurs have grown into elaborate and faintly scary sprites, and sprouted a health bar, as they are now able to take multiple hits.
The levels stretch first over two screens and then horizontally, leaving you scurrying from one side to the other to track enemies and deploy bubbles. And the roles of those bubbles themselves have expanded as well, with new variants accompanying DS-specific tricks, such as fans which can be blown into action (via the microphone) to waft them upwards.
It's unquestionably a thoroughly modern take on an old idea, but its efforts are torpedoed by the presence of a solid port of the original game on the same card. Lean, compact and humming with clockwork precision, classic Bubble Bobble makes the New Age mode feel like old hat. It's still repetitive and infuriatingly unforgiving, but it has character and compulsion in spades. It's hard to think of two more admirable qualities for a handheld game to exhibit, but it's harder still to be particularly excited by the arrival of another classic on yet another platform.
Whether you think the appearance of a game like this on DS is a crucial step in conserving gaming's heritage, or a total reversal of everything the machine was supposed to deliver, you'll most likely greet Bub and Bob with little more than familiar affection.