Will someone please explain the scoring mechanism for DDP? What is this 2x multiplier of which thou speakest? Etc. etc.
The 2x multiplier is the bomb max multiplier - i.e., if you're at max bombs, and then get a bomb, then the max bomb multiplier activates and gives you a constant point stream multiplied by 1. the multiplier and 2. your highest hit chain number. For each bomb you collect while the bonus is active, the multiplier number goes up by 1 - so if you've reached stage 5 without dying/bombing, for instance, assuming you've hit a decent chain somewhere you'll be getting millions of points in matters of seconds without even doing anything.
That's around half the scoring (or more if you're not good at chaining) - the other half is, er, the chaining. :V Pretty self-explanatory - bigger chains = more points, try to learn full stage chain routes for more points. The two easiest big chains to get in the game is the Stage 2 full chain which is still kind of tricky but becomes way easier after you practice it, which will net you 460-470 hits (13 million points give or take), and the crazy streaming section in Stage 5 which'll get you about 400 or so. IIRC you can do full chains of Stages 2, 4, 5 and 6, but 4-6 are really, really difficult to do that for. On the other hand a full chain of stage 5 or 6 will get you about 40 million, so it's worth it if you're good enough (I am not).
Also, ninja'd by Matsuri :< But yeah, it is really strict. On the other hand, though, the smallest of improvements will pretty much increase your score exponentially due to the nature of the system, so it's not all bad. :V