US physical software sales in May were down 44 per cent year-on-year, according to NPD figures, despite a significant surge in 3DS software sales.
NPD blames the declines largely on the PC sector, which it says experienced "sharp year-over-year declines ... due to poor comparisons to last year's Diablo 3 release".
Nintendo's 3DS topped the overall hardware sales charts, bolstered by a 60 per cent incline in software sales over May 2012. Three 3DS titles made the top-10 chart for physical software sales.
Microsoft's Xbox 360 was the top-selling home console for the 29th consecutive week, with sales of around 114,000, the firm said today.
Warner's Injustice: Gods Among Us remained the top-selling title at physical retail in US for the month, holding off Activision's Call of Duty: Black Ops 2 and Nintendo's Donkey Kong Country Returns in second and third respectively.
"Softness in new physical entertainment software sales stemmed from a decline in the number of new launches, with over 30% fewer new SKUs, as well as poor performance of the new SKUs that were released," said NPD.
"New SKUs generated over seventy percent less units on a per-SKU basis, and a decrease of over eighty percent revenue per SKU."
"Overall new launch performance in May'13 was poor, down 84% in units, decreasing 88% in dollars, which was driven by PCs and Consoles as new launches for portables were up 5% in units, and down only 7% in dollars," it added.
Note: these figures exclude income derived from digital sales, online retail, the used game trade, as well as micro-transactions, DLC and mobile games.