It looks as though mobile game downloads could use a jolt. More people are playing games than ever before, but they’re not downloading them at any greater rate.

That’s a finding from M:Metrics, which discovered nearly three-fourths of the 98.4 million people in France, Germany, Italy, Spain, the United Kingdom and the United States that played a mobile game in December did so via one found natively on the device. Some 38.5 million, or 8.8%, of mobile subscribers played a game they had downloaded and stored on their phone, a number that has been relatively flat compared with the year before, according to M:Metrics.

Only about 3.3% of mobile subscribers in the United States and Western Europe downloaded a game in December, versus 3.6% the year prior. Spain has the highest penetration of those playing a downloaded game and the highest rate of mobile game downloads. France lags all other markets.

There might be more opportunity in the area of smartphones. Smartphone owners are more avid users of mobile content, including games. In the United Kingdom, about 17% of smartphone owners played downloaded games in a month during Q4 2007 compared with just 9.8% of non-smartphone owners, M:Metrics says.