Gran, he's talking about the fact that HS sold under 100k copies in it's first week, PAL territory cumes have been pretty bad (PAL Irish charts have HS dropping to #19 at just week #2).
From a developer/software standpoint, it doesn't matter too greatly much if a game scores over 80% if no one ever buys it.
Also, Parroki, there's a very simple explanation about DQS's quick drop:
DQS was VERY supply constrained on week 1. It obviously sold out. The issue is that DQS is a very, very short, and easy-to-beat game. The Japanese have a very strong habit of playing a game, beating it, then re-selling it to the store, kinda like a rental.
The huge problem with DQS was that once the second week of shipments hit, so did the piles of used copies of DQS. Japanese are rather thrifty (imo), so they are far more inclined to buy a 4000yen used copy vs. a 5000yen new copy. The demand for the game was there to sell more, but like many games, the core gameplay was far too simplistic for the owners to hold onto, and continue to play long enough to force purchasers to buy new, and not used.
This is why many RPGs die so quickly in Japan - many can beat the games in 1-2 weeks, then resell pretty easy. Whereas brain training games, and such, have enough gameplay mechanics to give users a precieved value that the game should be kept, and not resold.
Now, you can see DQS for what it really should sell - after bottoming out in the sub-10k sales charts, it's begun to hold real well, and should sell another 50,000+ new copies. Why? Because eventually, your going to reach a good parity of used copies sold to the stores and rebought vs. new copies being bought. I am sure that if DQS wasn't so crappy (in terms of length and difficulty), it would of sold 750k or even 1m by now. But that's a major fault on SE's end of making the game just "too casual". Because even if it's casual, that doesn't mean it has to be so freaking short, and little replay value.
This is exactly why games like Oblivion for X360 (in Japan), or Western FPS games have rather good multipliers - core mechanics are good. Likewise for Wii Sports in Japan - it's a fun title that people paid very little for, and has enough of a precieved value (ie, its real cheap) that they wouldn't be able to sell it back and justify doing such. It's all about economics.
Back from the dead, I'm afraid.
