The latest April U.S. game sales have revealed Guerrilla Games'debuting outside the Top 20 and selling 58,000 copies for the month, NPD has told Gamasutra, as it slows to 677,000 lifetime U.S. sales.As part of the exclusive statistics provided to Gamasutra in its April 2009 NPD analysis , the key PlayStation 3-exclusive title, which debuted on February 27th, is still selling solidly, but at reduced numbers compared to its first two months.Even releasing so late in February, the title reached No.5 on the February 2009 NPD chart , selling 323,000 units, many of them likely in pre-orders from major retailers such as GameStop.In March, it continued strong sales , making No. 7 on the chart with 296,000 units sold in the United States, but an overall slow April has majorly reduced its sell-through, dropping it out of the Top 20.As part of its responses to March's NPD numbers, Sony announced that sales of the title had reached 1 million worldwide, and was the fastest Sony-published title in the U.S. to reach 500,000 unit sales.The company particularly commented that"has garnered the biggest initial success at retail of any first party PS3 title to date, and will continue to drive incentive for hardware sales throughout the year."However, overall April 2009 sales were down 17% , with the PlayStation 3 selling just 127,000 units for the month, compared to 340,000 units of the Wii and 175,000 units for the Xbox 360.Therefore, it seems that the global recession and the hardware's slowdown -- as well as the slowdown of the built-up wave of pre-orders for-- has slowed the system-seller outside of the Top 20, at least for now.