As a result , analysts have lowered expectations for future music games ; projections for sales of DJ Hero , a spinoff of Guitar Hero published by Activision , have been reduced from 1.6 million units in the first quarter of sales in the United Sates to only 600,000 . As a result , analysts have lowered expectations for future music games ; projections for sales of DJ Hero , a spinoff of Guitar Hero published by Activision , have been reduced from 1.6 million units in the first fiscal quarter of sales in the United Sates to only 600,000 .