an exhaustive analysis of Xbox Live Arcade sales, Metacritic scores, and trends over the past few years in a four-part writeup. The most interesting finding in the article, in our estimation, is how the perception of rising prices squares with reality. Yes, there are more 1200 point ($15) games being released on the service as compared to previous years, but there are more 800 point ($10) games coming out as well, and there are more of those than $15 games. The average is rising overall, but it hasn't yet reached the 1200 point mark, even if that price is being assigned to some of the more high profile (and high quality) games on the service.
The quality of the Summer of Arcade, on the other hand, is dropping overall, according to the average price and Metacritic score. In 2008, the first year the promotion existed, the games had an average Metacritic score of 84.8, with an average price of 960 points. This past year, however, the Metacritic score dropped to 78.8 (which still isn't too bad), but the average price was at 1120. This is purely mathematical, remember: The games are probably more complex these days, which allows Microsoft to set a higher price, and reviews on any site are subjective.
Finally, XBLA Fans found 73% of titles on XBLA have gone on sale within their first year, though many of the games on XBLA were only on sale for a day or so. That means that patient XBLA buyers can save a lot of money, if they pay attention and move quickly. There are a few other interesting conclusions in the analysis as a whole, and lots of insight on how Microsoft's Arcade has developed over the past few years.