Aliens: Colonial Marines has managed the biggest launch of the year so far in the UK, according to UKIE. The game has easily debuted at number one in the charts, and managed to sell more copies in its opening week than any other game that has launched so far this year (including Ni no Kuni and Dead Space 3), despite critics generally agreeing that it's a bad game.
Of course, it's only February, so there haven't been very many big launches so far to challenge Aliens: Colonial Marines. And the embargo on reviews means that those fans who planned to buy the game on launch day will have had no warning as to its quality. Presumably a lot of those who did buy the game the day it came out will be either exchanging it (if they can) or trading it in, but that won't affect these initial data on sales.
This highlights the disparity between sales and quality quite nicely, which is why so many people are getting worked up about it. But at the end of the day, it's sales figures that the publishers care about, and as long as they can boast about a debut at number one they'll selectively ignore negative reviews.
That said, we should see a drop in sales come next week. Dead Space 3, last week's number one and generally considered to be a decent game, has fallen to number two after a 57% decrease, so we can expect similar (if not much worse) for Aliens: Colonial Marines. Expect to see Crysis 3 on top next Monday.
