PopCap Games plans to double its Dublin workforce to 110 over the next "two to three years".
The 'Plants vs Zombies' creator set up a European HQ in Dublin six years ago.
Accounts just filed show the Seattle company suffered a 55pc decline in revenue in 2009, as sales fell from €10.2m to €6.7m.
Senior director Cathy Orr said the firm was still on the up, adding that the 2009 accounts were not comparable to 2008's as the European and Asian operations were split in 2009.
PopCap also changed the way it recognises revenues in Ireland in 2009. The Dublin unit "enjoyed increased profits in 2010", she added.
PopCap secured a €480,000 research & development grant from the IDA in June 2009 and got a capital contribution of €471,000 from its parent.