For the first six months of this year, Disney's share of the market grew to 11.3 percent, according to PC Data, an industry research publication.
The iMac, PC Data said, is now the third-best-selling computer model in the country.
"You have all the movie people throwing money at this," said Ann Stephens, the president of PC Data, a market research firm.
For its part, Sony ranked No. 10, with a market share of 1.6 percent, PC Data estimated.
The series was canceled, but the game has grossed more than $5 million, according to PC Data, a market research firm.
Sales of children's game software increased from $6.3 million in 1995 to $92 million last year, according to PC Data.
Tax Cut sold 154,270 units in January, nearly seven times its sales a year earlier, PC Data said.
PC Data, based in Reston, Va., has become the latest market research firm to enter the fray.
While this might sound novel, PC Data is playing catch up.
Five of the 20 top-selling computer games last year were low-cost hunting titles, according to PC Data, a research firm.