Nintendo is fighting a EUR 149.1 million (USD 232 million) fine levied against it by EU regulators for price fixing.
According to a Bloomberg report, the company contends that the calculation of the fine was irrational and discriminatory.
"The penalty was unfair, illegal, even shocking," Ian Forrester, representing Nintendo, told the European Court of First Instance in Luxembourg.
"This remains one of the biggest single fines in EU competition law."
The penalty was imposed in 2002 when Nintendo and seven distributors were found to have colluded to raise hardware and software prices between 1991 and 1998.
"The fine was not of a capricious nature, or based on wild estimates," said Xavier Lewis, a commission lawyer.
"This fine was for an infringement that was considered very serious."
We will have more on this story - specifically, whether or not Nintendo is successful in having the fine reduced - when the court makes a decision.